Kelvin to Delisle Converter
Convert kelvins to degrees Delisle with our free online temperature converter.
Quick Answer
1 Kelvin = 558.225 degrees Delisle
Formula: Kelvin × conversion factor = Delisle
Use the calculator below for instant, accurate conversions.
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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Kelvin to Delisle Calculator
How to Use the Kelvin to Delisle Calculator:
- Enter the value you want to convert in the 'From' field (Kelvin).
- The converted value in Delisle will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Temperature category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Kelvin to Delisle: Step-by-Step Guide
Temperature conversions like Kelvin to Delisle use specific non-linear formulas.
Formula:
First convert K to °C: °C = K - 273.15. Then convert °C to °De: °De = (100 - °C) × 3/2Example Calculation:
Convert 10K:
1. °C = 10 - 273.15 = -263.15°C
2. °De = (100 - -263.15) × 3/2 = 544.7°De
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
Need to convert to other temperature units?
View all Temperature conversions →What is a Kelvin and a Delisle?
Kelvin (symbol: K, not °K) is the base unit of thermodynamic temperature in the International System of Units (SI). It is an absolute temperature scale, meaning its zero point (0 K) represents the lowest theoretically possible temperature.
Key characteristics:
- Absolute zero: 0 K = -273.15°C = -459.67°F
- No negative temperatures: (in ordinary matter)
- No degree symbol: Write "273 K" not "273°K"
- Same magnitude as Celsius: 1 K change = 1°C change
Modern Definition (2019): The kelvin is defined by fixing the numerical value of the Boltzmann constant (k) to exactly 1.380649×10⁻²³ joules per kelvin (J/K). This definition links temperature to energy at the atomic level.
Conversion formulas:
- From Celsius: K = °C + 273.15 - Convert C to K
- From Fahrenheit: K = (°F - 32) × 5/9 + 273.15 - Convert F to K
- To Celsius: °C = K - 273.15 - Convert K to C
- To Fahrenheit: °F = (K - 273.15) × 9/5 + 32 - Convert K to F
Important fixed points:
- Absolute zero: 0 K (exactly)
- Water triple point: 273.16 K (0.01°C) - where ice, water, and vapor coexist
- Water freezing: 273.15 K (0°C)
- Water boiling: 373.15 K (100°C)
- Room temperature: ~293 K (20°C)
- Human body: ~310 K (37°C)
Why no degree symbol? Kelvin is an absolute scale starting from a fundamental physical limit (absolute zero), not an arbitrary reference point like Celsius or Fahrenheit. The unit is "kelvin" (lowercase when spelled out), not "degrees Kelvin."
Convert between temperature units: Kelvin converter
The Delisle scale (symbol: °De or °D) is an inverted temperature scale that divides the interval between the boiling point and freezing point of water into 150 equal divisions under standard atmospheric pressure, with numerical values decreasing as temperature increases.
Scale Calibration (Inverted)
Fixed Points:
- Boiling point of water: 0 degrees Delisle (0°De) - the ZERO reference
- Freezing point of water: 150 degrees Delisle (150°De) - 150° higher than boiling
- Degree size: Each Delisle degree = 2/3 Celsius degree (or 0.667°C)
The Inversion: Unlike Celsius, Fahrenheit, Réaumur, and Kelvin, which all increase with temperature:
- Hotter temperatures = LOWER Delisle numbers (approaching 0°De)
- Colder temperatures = HIGHER Delisle numbers (above 150°De)
- Temperature increases = Delisle decreases
Mathematical Relationships
Delisle to Celsius:
- °C = 100 - (°De × 2/3)
- Or: °C = 100 - (°De ÷ 1.5)
Celsius to Delisle:
- °De = (100 - °C) × 3/2
- Or: °De = (100 - °C) × 1.5
Delisle to Fahrenheit:
- °F = 212 - (°De × 6/5)
- Or: °F = 212 - (°De × 1.2)
Examples:
- 0°De = 100°C (boiling water)
- 75°De = 50°C (halfway between boiling and freezing)
- 150°De = 0°C (freezing water)
- 300°De = -100°C (extreme cold, -148°F)
Why 150 Degrees?
Delisle chose 150 degrees for the freezing point due to:
- Mercury contraction observation: His mercury thermometers showed 150 units of contraction between boiling and freezing
- Divisibility: 150 = 2 × 3 × 5², offering factors (2, 3, 5, 6, 10, 15, 25, 30, 50, 75, 150)
- Convenient fractional divisions: 150/3 = 50°, 150/2 = 75°, 150/10 = 15° for practical measurements
- Empirical basis: Based on actual instrument behavior rather than abstract decimal preference
Why Invert the Scale?
Delisle's inversion was methodological rather than arbitrary:
Calibration Process:
- Started with boiling water (100°C) as reference point zero
- Observed mercury column contraction as water cooled
- Counted degrees of contraction downward from boiling
- At freezing point (0°C), mercury had contracted 150 divisions
Result: A scale that measured "degrees of cooling" from boiling, making hotter temperatures numerically smaller. While counterintuitive by modern standards, it reflected the experimental process.
Note: The Kelvin is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Delisle belongs to the imperial/US customary system.
History of the Kelvin and Delisle
-
Early Thermodynamics (1840s): Scientists studying heat engines and thermodynamics realized that there must be a lowest possible temperature, where thermal energy reaches its minimum.
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William Thomson (Lord Kelvin) (1824-1907): British physicist and engineer who proposed the absolute temperature scale in 1848. He later became Baron Kelvin, and the unit was named in his honor.
-
Original Proposal (1848): Thomson proposed an absolute thermodynamic temperature scale based on:
- Carnot's theorem on heat engines
- The idea that there exists a temperature at which thermal motion ceases
- Independence from the properties of any particular substance
-
Determination of Absolute Zero: By studying the thermal expansion of gases, scientists extrapolated that gases would theoretically have zero volume at approximately -273°C. This temperature was identified as absolute zero.
-
Original Scale (1848-1954): Thomson's scale was initially called the "absolute scale" or "thermodynamic temperature scale." It used the same degree size as Celsius but started at absolute zero.
-
Triple Point Definition (1954): The 10th CGPM (General Conference on Weights and Measures) officially named the unit "kelvin" (symbol K) and defined it based on the triple point of water:
- Triple point of water = exactly 273.16 K
- This made the kelvin equal in magnitude to the Celsius degree
- Eliminated need for a physical artifact
-
Why 273.15?: This value was chosen to maintain compatibility with the Celsius scale, ensuring that the freezing point of water remained at 0°C (273.15 K) and boiling point at 100°C (373.15 K).
-
Adoption as SI Base Unit (1960): When the International System of Units (SI) was established, the kelvin was designated as one of the seven SI base units for thermodynamic temperature.
-
Symbol Change (1967): The symbol was changed from "°K" (degree Kelvin) to just "K" (kelvin) to emphasize its absolute nature and distinguish it from relative scales.
-
2019 Redefinition: On May 20, 2019, the kelvin was redefined based on the Boltzmann constant:
- Old definition: Based on triple point of water (273.16 K)
- New definition: Boltzmann constant fixed at exactly 1.380649×10⁻²³ J/K
- Why: Links temperature to fundamental physics (energy per particle)
- Advantage: Can be reproduced in any properly equipped laboratory
- Impact: No change to the scale's size or zero point, only how it's realized
-
Boltzmann Connection: The Boltzmann constant (k) relates the average kinetic energy of particles to temperature: E = (3/2)kT. By fixing k, temperature is now defined through energy.
-
Global Scientific Standard: The kelvin is the only SI base unit for temperature. It's used universally in:
- Physics research
- Chemistry
- Astronomy and astrophysics
- Engineering
- Materials science
- Climate science
-
Practical Usage: While Celsius dominates everyday life in most countries and Fahrenheit in the US, scientists worldwide use kelvin for research, ensuring universal compatibility and precision.
The Delisle scale's 290-year history is inseparable from the development of Russian science and the Imperial Academy's early years.
Joseph-Nicolas Delisle (1688-1768)
Born in Paris to artistic parents, Delisle became one of France's leading astronomers, specializing in celestial mechanics and cartography. His work on planetary transits and lunar theory earned him election to the French Academy of Sciences (1714) and international recognition.
1725: Invitation to Russia
Tsar Peter the Great, determined to modernize Russia through Western science, invited Delisle to St. Petersburg to establish an astronomical observatory and help found the Imperial Russian Academy of Sciences. Delisle arrived in St. Petersburg in August 1725, months after Peter's death, but Empress Catherine I honored the invitation.
1725-1747: Russian Academy Directorship
As the Academy's first director of astronomy, Delisle:
- Established St. Petersburg Observatory (1726)
- Trained Russian astronomers and instrument makers
- Standardized scientific measurements across the Russian Empire
- Corresponded with European scientific societies
Creation of the Delisle Scale (1732)
The Problem: Russia's vast territory and extreme climate variations required standardized temperature measurements for meteorology, agriculture, and scientific research. Existing thermometers used inconsistent scales, making comparison impossible.
Delisle's Solution (1732):
- Boiling water reference: Started with boiling point as 0° (easiest to reproduce reliably)
- Mercury contraction: Observed mercury column shrinking as temperature decreased
- Freezing point calibration: Marked freezing water at 150° of contraction
- Uniform divisions: Divided the interval into 150 equal degrees
1732 Paper: Delisle presented his scale to the Imperial Russian Academy, arguing that starting from boiling point provided greater calibration accuracy than starting from freezing (where ice-water mixtures could vary slightly).
Official Adoption in Russia (1738-1840s)
1738: Imperial Decree
The Russian Imperial government officially adopted the Delisle scale for all government and scientific purposes, making Russia the first nation to standardize on a single temperature scale nationwide.
Implementation:
- Meteorological stations: All Russian weather observation posts used Delisle thermometers
- Scientific research: Academy publications reported temperatures in Delisle
- Military applications: Army and Navy used Delisle for weather reporting
- Educational institutions: Russian universities taught Delisle as standard
Geographic Spread: The scale's use extended across the Russian Empire:
- St. Petersburg and Moscow (primary centers)
- Baltic provinces (Estonia, Latvia, Lithuania)
- Siberian outposts and exploration expeditions
- Crimea and southern territories
Coexistence with Réaumur (1780s-1840s)
By the late 18th century, Western European science had largely standardized on Réaumur (continental Europe) or Fahrenheit (Britain), creating communication challenges for Russian scientists.
1780s-1820s: Gradual Transition
Russian instrument makers began producing dual-scale thermometers (Delisle/Réaumur) to facilitate:
- International scientific correspondence
- Translation of Western European research
- Trade with European partners
1840s: Réaumur Dominance
By the 1840s, Réaumur had effectively replaced Delisle in Russian scientific practice:
- Younger Russian scientists trained with Réaumur
- International standardization pressure increased
- French scientific influence (Réaumur) outweighed earlier German connections
Final Decline (1850-1917)
1850-1870: Delisle relegated to historical archives, antique thermometers, and elderly scientists' habit 1871: German unification's adoption of Celsius influenced Russian scientific circles 1900-1917: Celsius gaining ground in Russian universities and research institutions 1917-1925: Bolshevik Revolution brought metric system adoption, officially ending Delisle use
Legacy and Modern Recognition
The Delisle scale survives as:
- Historical curiosity: The only inverted scale to achieve governmental adoption
- Archival research: Russian meteorological data (1738-1840s) requires Delisle conversion
- Thermometer collecting: Delisle/Réaumur dual-scale antique thermometers from Russia
- Scientific history: Example of how methodology (cooling observation) shaped measurement design
Common Uses and Applications: kelvins vs degrees Delisle
Explore the typical applications for both Kelvin (imperial/US) and Delisle (imperial/US) to understand their common contexts.
Common Uses for kelvins
The kelvin is the standard temperature unit in scientific and technical fields worldwide:
Scientific Research
The universal temperature unit in physics, chemistry, and all scientific disciplines. Essential for ensuring reproducibility and international collaboration.
Scientific applications:
- Thermodynamics and statistical mechanics
- Quantum mechanics and atomic physics
- Chemical kinetics and equilibrium
- Materials science research
- Particle physics experiments
- Cryogenics and low-temperature physics
Why kelvin in science:
- SI base unit (international standard)
- Absolute scale (no negative temperatures)
- Direct relationship to energy (via Boltzmann constant)
- Universal reproducibility
- Required for scientific publications
Convert for scientific work: kelvins to other units
Astronomy and Astrophysics
Standard for measuring stellar temperatures, cosmic phenomena, and space science.
Astronomical uses:
- Star surface temperatures (spectral classification)
- Stellar core temperatures
- Planetary atmosphere temperatures
- Cosmic microwave background (2.7 K)
- Interstellar medium temperature
- Black hole thermodynamics
- Big Bang cosmology
Why kelvin in astronomy:
- Suitable for extreme temperatures (millions of kelvins)
- No confusion with negative values
- International astronomical standard
- Links to blackbody radiation physics
Color Temperature
Standard for describing the color of light sources in photography, cinematography, and lighting design.
Color temperature uses:
- Light bulb specifications (2,700-6,500 K)
- Camera white balance settings
- Video production lighting
- Architectural lighting design
- Display calibration
- Stage and theater lighting
Common values:
- Warm light: 2,700-3,500 K
- Neutral/daylight: 5,000-6,500 K
- Cool light: 6,500-10,000 K
Cryogenics
Essential for ultra-low temperature applications and liquefied gas handling.
Cryogenic applications:
- Liquid nitrogen storage (77 K)
- Liquid helium systems (4 K)
- Superconducting magnets (MRI, particle accelerators)
- Cryopreservation (biological samples)
- Rocket fuel (liquid hydrogen, liquid oxygen)
- Low-temperature physics research
Why kelvin in cryogenics:
- Natural scale for very low temperatures
- Avoids large negative numbers
- Direct relationship to thermal energy
- Industry standard
Materials Science
Critical for studying phase transitions, material properties, and thermal behavior.
Materials applications:
- Melting and boiling points
- Glass transition temperatures
- Superconductor critical temperatures
- Thermal expansion studies
- Heat capacity measurements
- Crystal structure studies
Engineering and Industry
Used in technical specifications where absolute temperature is important.
Engineering uses:
- Thermodynamic calculations (heat engines, refrigeration)
- Gas laws and ideal gas calculations
- Chemical reactor design
- Aerospace engineering (re-entry heat)
- Semiconductor manufacturing
- Industrial process control
Ideal gas law: PV = nRT (where T must be in kelvins)
Climate Science
Standard for scientific climate modeling and atmospheric research.
Climate uses:
- Atmospheric temperature profiles
- Ocean temperature measurements
- Climate model simulations
- Radiative transfer calculations
- Greenhouse gas physics
- Ice core data analysis
Use our kelvin converter for scientific conversions.
When to Use degrees Delisle
Historical Russian Meteorology (1738-1840s)
The primary application of the Delisle scale was Russian weather observation:
Imperial Meteorological Network:
- St. Petersburg Observatory: Daily temperatures recorded in Delisle
- Moscow weather stations: Imperial Academy network standardized on Delisle
- Siberian frontier posts: Military expeditions reported temperatures in Delisle
- Black Sea and Baltic ports: Naval meteorological data in Delisle
Record Keeping: Archives from this period contain:
- Handwritten logbooks with Delisle readings
- Published annual weather summaries
- Agricultural yield correlations with Delisle temperatures
- Military campaign weather reports (e.g., Napoleon's 1812 invasion)
18th-Century Russian Scientific Research
Russian Academy scientists used Delisle for:
Physics Experiments:
- Thermal expansion studies
- Phase transition research (freezing, melting, boiling)
- Instrument calibration standards
Biological Research:
- Plant growth temperature requirements
- Animal physiology studies
- Seed germination experiments
Astronomical Observations:
- Observatory temperature logs (affecting telescope precision)
- Atmospheric refraction corrections based on temperature
Historical Document Interpretation
Modern researchers encounter Delisle in:
Russian Imperial Archives:
- Government reports (1738-1840s)
- Military campaign records
- Agricultural survey data
- Medical records from Russian hospitals
Scientific Publications:
- Imperial Russian Academy journals
- European scientific correspondence with Russian researchers
- Exploration expedition reports (Bering, Kamchatka expeditions)
Literature and Personal Correspondence:
- Letters between Russian aristocracy
- Travel journals of European visitors to Russia
- Historical novels set in 18th-19th century Russia
Antique Thermometer Collecting
Delisle thermometers are rare and valuable collectibles:
Rarity Factors:
- Limited production period: 1732-1850s primarily
- Geographic concentration: Almost exclusively Russian Empire
- Destruction: Many lost during Russian Revolution, World Wars
- Dual-scale models: Delisle/Réaumur thermometers from 1780s-1840s most sought
Market Value:
- Original Delisle thermometers: $1,000-$10,000+ (extreme rarity)
- Dual-scale Delisle/Réaumur: $800-$5,000 (more common)
- Reproductions/modern curiosities: $50-$200
Education and Science Museums
Science museums use Delisle thermometers to teach:
- History of measurement: Evolution of temperature scales
- Scientific methodology: How observation shapes measurement design
- Cultural context: Russian Empire's scientific development
- Inverted scales: Challenging students' assumptions about "hotter = higher number"
Online Temperature Converters
Delisle appears in comprehensive temperature conversion tools:
- Historical conversion calculators for archival research
- "Exotic scales" demonstrations alongside Rømer, Newton scales
- Educational tools teaching temperature scale diversity
Additional Unit Information
About Kelvin (K)
What is absolute zero?
Absolute zero is 0 K (0 kelvins), which equals -273.15°C or -459.67°F. It's the lowest theoretically possible temperature.
What happens at absolute zero:
- All classical thermal motion of particles stops
- Particles still have quantum mechanical zero-point energy
- Entropy reaches its minimum value (Third Law of Thermodynamics)
- No heat energy can be extracted
Can we reach absolute zero?
- No: Third Law of Thermodynamics says it's impossible to reach in finite steps
- Close approach: Scientists have reached temperatures within billionths of a kelvin
- Asymptotic: Can get arbitrarily close but never exactly 0 K
Why impossible?
- Would require infinite work to remove all thermal energy
- Quantum mechanics prevents complete stillness (zero-point energy)
- Heisenberg uncertainty principle limits precision
Coldest achieved: ~100 picokelvin (0.0000000001 K) in ultra-cold atom experiments
How do you convert Celsius to Kelvin?
Use the formula: K = °C + 273.15
Step-by-step:
- Take the Celsius temperature
- Add 273.15
- Result is in kelvins
Examples:
- 0°C: 0 + 273.15 = 273.15 K (water freezes)
- 20°C: 20 + 273.15 = 293.15 K (room temp)
- 100°C: 100 + 273.15 = 373.15 K (water boils)
- -40°C: -40 + 273.15 = 233.15 K
- -273.15°C: -273.15 + 273.15 = 0 K (absolute zero)
Reverse conversion (Kelvin to Celsius):
- Formula: °C = K - 273.15
- Example: 300 K = 300 - 273.15 = 26.85°C
Why 273.15?
- This offset ensures water freezes at 0°C (273.15 K) and boils at 100°C (373.15 K)
- Maintains same degree size as Celsius
Use our Celsius to Kelvin converter for instant conversions.
Why doesn't Kelvin use the degree symbol?
Kelvin doesn't use the degree symbol (°) because it's an absolute scale, not a relative one.
The reasoning:
- Absolute scale: Starts at absolute zero (a fundamental physical limit), not an arbitrary reference point
- Not "degrees": The term "degree" implies divisions on a scale between arbitrary points
- Official designation: Write "300 K" or "300 kelvins", never "300°K"
Comparison:
- Celsius: 0°C is arbitrary (water freezing), uses degree symbol
- Fahrenheit: 0°F is arbitrary (brine freezing), uses degree symbol
- Kelvin: 0 K is absolute zero (fundamental), no degree symbol
Historical note:
- Originally written as "°K" (degrees Kelvin)
- Changed to just "K" (kelvin) in 1967
- Emphasizes its absolute nature
Other absolute scale:
- Rankine (°R) - absolute Fahrenheit scale, does use degree symbol (less common)
What is the relationship between Kelvin and Celsius?
Kelvin and Celsius have the same degree size, but different zero points.
Key relationships:
- Conversion: K = °C + 273.15
- Same magnitude: 1 K change = 1°C change
- Different zeros: 0 K = -273.15°C
Temperature difference:
- A change of 5°C = a change of 5 K
- If temp increases from 20°C to 25°C, that's a 5°C (or 5 K) increase
- 293.15 K to 298.15 K = same increase
Fixed points:
- Water freezes: 0°C = 273.15 K
- Water boils: 100°C = 373.15 K
- Difference: 100°C = 100 K
Why same size:
- Kelvin was defined to maintain compatibility with Celsius
- Makes conversion simple (just add/subtract 273.15)
- Scientists can use either for temperature differences
Convert between them: K to C | C to K
How do you convert Fahrenheit to Kelvin?
Formula: K = (°F - 32) × 5/9 + 273.15
Step-by-step:
- Subtract 32 from Fahrenheit
- Multiply by 5/9 (or 0.5556)
- Add 273.15
Examples:
- 32°F: (32 - 32) × 5/9 + 273.15 = 273.15 K (water freezes)
- 68°F: (68 - 32) × 5/9 + 273.15 = 293.15 K (room temp)
- 212°F: (212 - 32) × 5/9 + 273.15 = 373.15 K (water boils)
- -40°F: (-40 - 32) × 5/9 + 273.15 = 233.15 K
Reverse conversion (Kelvin to Fahrenheit):
- Formula: °F = (K - 273.15) × 9/5 + 32
- Example: 300 K = (300 - 273.15) × 9/5 + 32 = 80.33°F
Alternative method:
- Convert °F to °C first: °C = (°F - 32) × 5/9
- Then convert °C to K: K = °C + 273.15
Use our Fahrenheit to Kelvin converter for accurate conversions.
What is room temperature in Kelvin?
Room temperature is approximately 293-295 K, which equals 20-22°C (68-72°F).
Standard definitions:
- Scientific standard: 293.15 K (20°C, 68°F)
- Comfortable range: 293-295 K (20-22°C, 68-72°F)
- IUPAC standard: 298.15 K (25°C, 77°F) for chemistry
Common room temps:
- Cool room: 291 K (18°C, 64°F)
- Comfortable: 293 K (20°C, 68°F)
- Warm room: 296 K (23°C, 73°F)
Context matters:
- Laboratories: Often use 293.15 K or 298.15 K as standard
- Home comfort: 293-295 K typical
- Chemical reactions: Often specified at 298 K
Human body comparison:
- Room temp: 293 K
- Body temp: 310 K (37°C)
- Difference: 17 K (or 17°C)
What is color temperature measured in?
Color temperature is measured in kelvins (K).
What it means: Color temperature describes the color appearance of light by comparing it to the color of light emitted by a theoretical "blackbody" heated to that temperature.
Common color temperatures:
- 1,800-2,000 K: Candle flame (warm orange)
- 2,700 K: Incandescent bulb (warm yellow)
- 3,000 K: Halogen bulb (warm white)
- 5,000 K: Daylight (neutral white)
- 5,500-6,000 K: Electronic flash (bright white)
- 6,500 K: Overcast daylight (cool white)
- 10,000+ K: Clear blue sky (very cool blue)
Photography use:
- Cameras adjust white balance based on color temperature
- Tungsten setting: ~3,200 K
- Daylight setting: ~5,600 K
Not actual temperature:
- Light bulb at 2,700 K color temp isn't actually 2,700 K hot
- Refers to color match with blackbody at that temperature
- LED bulbs cool to touch but have high color temperature
Can temperature be negative in Kelvin?
In ordinary circumstances, no. Temperatures in kelvin cannot be negative because 0 K is absolute zero, the lowest possible temperature.
For ordinary matter:
- 0 K is the theoretical minimum
- All physical temperatures are ≥ 0 K
- Negative kelvin would be "colder than absolute zero" - impossible
Exotic exception (negative absolute temperature):
- In special quantum systems, "negative temperature" exists in thermodynamic sense
- NOT colder than absolute zero - actually infinitely hot!
- Occurs in population-inverted systems (lasers, certain spin systems)
- Highly technical and non-intuitive concept
If you calculate negative K:
- You made an error in your conversion
- Check your formula (especially converting from Fahrenheit)
Bottom line: For all practical purposes and everyday physics, temperatures in kelvin are always positive (≥ 0 K).
How is Kelvin different from Celsius?
Kelvin and Celsius differ in their zero point, but have the same degree size.
Key differences:
| Feature | Kelvin | Celsius | |---------|--------|---------| | Zero point | Absolute zero (-273.15°C) | Water freezing (0°C) | | Freezing point | 273.15 K | 0°C | | Boiling point | 373.15 K | 100°C | | Degree symbol | No (just K) | Yes (°C) | | Scale type | Absolute | Relative | | Negative values | No (≥0 K) | Yes (below 0°C) | | Primary use | Science | Everyday (most countries) |
Conversion:
- K = °C + 273.15
- °C = K - 273.15
Same magnitude:
- 1 K change = 1°C change
- Temperature difference of 10°C = 10 K
When to use which:
- Kelvin: Scientific research, absolute calculations, thermodynamics
- Celsius: Daily life, weather, cooking (in metric countries)
Convert between them: K to C | C to K
What temperature is the Sun in Kelvin?
The Sun's surface (photosphere) temperature is approximately 5,778 K (5,505°C or 9,941°F).
Sun's temperature zones:
- Core: ~15,000,000 K (15 million K) - where fusion occurs
- Radiative zone: 7,000,000 K to 2,000,000 K
- Convective zone: 2,000,000 K to 5,800 K
- Photosphere (visible surface): 5,778 K - what we see
- Chromosphere: 4,000-25,000 K
- Corona (outer atmosphere): 1,000,000-3,000,000 K (paradoxically hotter than surface!)
Why kelvin for the Sun:
- Astronomical standard
- Suitable for extreme temperatures
- Links to blackbody radiation and stellar classification
Other stars:
- Red dwarfs: 2,500-4,000 K (cooler, redder)
- Sun-like stars: 5,000-6,000 K (yellow)
- Blue giants: 10,000-50,000 K (hotter, bluer)
Spectral classification: Based on surface temperature in kelvins
About Delisle (°De)
What are the freezing and boiling points of water in Delisle?
Water boils at 0°De and freezes at 150°De. This is inverted compared to all other major temperature scales (Celsius, Fahrenheit, Réaumur, Kelvin), where higher numbers indicate hotter temperatures.
Why does the Delisle scale decrease with increasing temperature?
Delisle's methodology determined the scale's direction:
- Calibration process: He started with boiling water (100°C) as his zero reference point
- Cooling observation: He watched mercury contract as water cooled from boiling
- Counting contraction: Each unit of contraction represented one Delisle degree
- Result: At freezing point, the mercury had contracted 150 divisions from boiling
The scale thus measured "degrees of cooling" from boiling water, making hotter temperatures numerically smaller. While counterintuitive, it reflected his experimental procedure.
How does Delisle relate to Celsius?
Conversion formulas:
- Delisle → Celsius: °C = 100 - (°De × 2/3)
- Celsius → Delisle: °De = (100 - °C) × 1.5
Relationship: Each Delisle degree = 2/3 Celsius degree (0.667°C), but running in opposite direction.
Example:
- 0°De = 100°C (boiling)
- 150°De = 0°C (freezing)
- 75°De = 50°C (midpoint)
The "100 -" in the formula accounts for the inversion.
Was the Delisle scale ever widely used?
Yes, in Imperial Russia (1738-1840s):
The Delisle scale was the official temperature standard of the Russian Empire for approximately one century. It was mandatory for:
- All government meteorological stations
- Imperial Russian Academy scientific research
- Military weather reporting
- Educational institutions
Not widely used elsewhere: Aside from Russia, Delisle remained a curiosity. Western Europe used Réaumur or Fahrenheit; Delisle was essentially a Russian phenomenon.
Why didn't other countries adopt the Delisle scale?
Several factors limited adoption:
- Counterintuitive: The inversion (hotter = lower number) confused users
- Late arrival: By 1732, Fahrenheit (1714) and Réaumur (1730) were established
- Geographic isolation: Russia's distance from Western European scientific centers
- Communication barriers: Language and political isolation limited dissemination
- No compelling advantage: The inversion offered no practical benefit over conventional scales
The scale succeeded in Russia due to Delisle's position at the Imperial Academy and government decree, not scientific merit.
How do you convert a Delisle temperature to Fahrenheit?
Two-step method:
- Convert Delisle to Celsius: °C = 100 - (°De × 2/3)
- Convert Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Direct formula: °F = 212 - (°De × 6/5) or °F = 212 - (°De × 1.2)
Example: 120°De (Russian "room temperature")
- Step 1: °C = 100 - (120 × 2/3) = 100 - 80 = 20°C
- Step 2: °F = (20 × 1.8) + 32 = 36 + 32 = 68°F
Direct: 212 - (120 × 1.2) = 212 - 144 = 68°F ✓
Can you still find Delisle thermometers?
Original antiques: Extremely rare and valuable
- Russian-made Delisle thermometers (1738-1850): $1,000-$10,000+
- Dual-scale Delisle/Réaumur (1780-1840): $800-$5,000
- Most survive in Russian museums, private collections, or academic institutions
Modern reproductions: Very limited availability
- Some specialty scientific instrument makers produce educational replicas
- Mostly for museum exhibits or science education purposes
- Generally not commercially available
Why so rare:
- Short production period (≈110 years)
- Limited geographic area (Russian Empire only)
- Wars and revolutions destroyed many (1812, 1917, WWII)
- Glass fragility means few survived intact
What does negative Delisle mean?
Negative Delisle = Above boiling point (>100°C):
Since 0°De = 100°C (boiling), temperatures above boiling would be negative:
- -15°De = 110°C (230°F) - pressurized water
- -30°De = 120°C (248°F) - autoclave sterilization
- -150°De = 200°C (392°F) - hot oven
Rarely used: Delisle's original design focused on ambient and cooling temperatures. High-temperature applications were uncommon in 18th-century Russia, so negative Delisle values are virtually absent from historical records.
How do historians handle Russian weather data in Delisle?
Conversion workflow:
- Identify Delisle readings in archival documents (e.g., "180 градусов Делиля" = 180 degrees Delisle)
- Apply conversion formula: °C = 100 - (180 × 2/3) = 100 - 120 = -20°C
- Convert to Fahrenheit if needed: (-20 × 1.8) + 32 = -4°F
- Document both original and converted values for scholarly accuracy
Example from historical record:
- Original: "Санкт-Петербург, 15 января 1740, 195°De" (St. Petersburg, January 15, 1740, 195°De)
- Conversion: 100 - (195 × 2/3) = 100 - 130 = -30°C = -22°F (severe cold)
Why is Delisle important to the history of science?
Scientific significance:
- Methodological diversity: Demonstrates how experimental procedure shaped measurement design
- Governmental standardization: First empire-wide temperature scale adoption (1738)
- Cultural context: Reflects Russian Empire's scientific modernization under Peter the Great's legacy
- Measurement evolution: Shows the pre-standardization diversity of temperature scales
- Unique inversion: Only inverted scale to achieve widespread official use
Lessons:
- Measurement standards require international consensus, not just local adoption
- Intuitive design matters for widespread acceptance
- Historical contingency (Delisle's Academy position) can temporarily override scientific merit
Are there any other inverted temperature scales?
No other major inverted scales achieved significant use.
Minor historical attempts:
- Some early thermometers were calibrated from hot to cold simply due to construction methods
- Individual scientists occasionally created personal inverted scales for specific experiments
Why Delisle is unique:
- Only inverted scale adopted by a government (Imperial Russia, 1738)
- Only inverted scale used for over a century
- Only inverted scale with substantial archival presence
All other successful temperature scales (Fahrenheit, Celsius, Réaumur, Kelvin, Rankine) use conventional orientation where higher numbers = hotter.
People Also Ask
How do I convert Kelvin to Delisle?
To convert Kelvin to Delisle, enter the value in Kelvin in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our temperature converter page to convert between other units in this category.
Learn more →What is the conversion factor from Kelvin to Delisle?
The conversion factor depends on the specific relationship between Kelvin and Delisle. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Delisle back to Kelvin?
Yes! You can easily convert Delisle back to Kelvin by using the swap button (⇌) in the calculator above, or by visiting our Delisle to Kelvin converter page. You can also explore other temperature conversions on our category page.
Learn more →What are common uses for Kelvin and Delisle?
Kelvin and Delisle are both standard units used in temperature measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our temperature converter for more conversion options.
For more temperature conversion questions, visit our FAQ page or explore our conversion guides.
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Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology — International Temperature Scale standards
Bureau International des Poids et Mesures — Definition of the kelvin and temperature scales
Last verified: February 19, 2026