Rømer to Delisle Conversion Calculator: Free Online Tool
Convert degrees Rømer to degrees Delisle with our free online temperature converter.
Rømer to Delisle Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Rømer).
- 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 Rømer to Delisle
Temperature conversions like Rømer to Delisle use specific non-linear formulas.
Formula:
First convert °Rø to °C: °C = (°Rø - 7.5) × 40/21. Then convert °C to °De: °De = (100 - °C) × 3/2Example Calculation:
Convert 10°Rø:
1. °C = (10 - 7.5) × 40/21 = 4.76°C
2. °De = (100 - 4.76) × 3/2 = 142.9°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.
What is a Rømer and a Delisle?
The Rømer scale (°Rø) is a historical temperature scale where the freezing point of water is set at 7.5 degrees and the boiling point at 60 degrees.
The Delisle scale (°De) is a historical temperature scale where the boiling point of water is set at 0 degrees and the freezing point at 150 degrees. The scale decreases as thermal energy increases.
Note: The Rømer 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 Rømer and Delisle
Invented by the Danish astronomer Ole Christensen Rømer in 1701. Rømer based his scale on two points: the freezing point of brine (0 °Rø) and the boiling point of water (60 °Rø). He later observed pure water froze at 7.5 °Rø. Daniel Fahrenheit visited Rømer and reportedly based his own scale on Rømer's work, multiplying the number of degrees by four.
Invented by the French astronomer Joseph-Nicolas Delisle in 1732 for use in Russia. He defined his scale with the boiling point of water as 0 °De and the freezing point as 150 °De. It was used primarily in Russia for about a century.
Common Uses for degrees Rømer and degrees Delisle
Explore the typical applications for both Rømer (imperial/US) and Delisle (imperial/US) to understand their common contexts.
Common Uses for degrees Rømer
- Historical Significance: Primarily of historical interest as a precursor to the Fahrenheit scale.
- Not used in modern scientific or general applications.
Common Uses for degrees Delisle
- Historical Significance: Of interest in the history of thermometry, particularly in Russia.
- Not used in modern scientific or general applications.
Frequently Asked Questions
Questions About Rømer (°Rø)
What are the freezing and boiling points of water in Rømer?
Water freezes at 7.5 °Rø and boils at 60 °Rø.
How did Rømer influence Fahrenheit?
Fahrenheit adopted Rømer's use of two reference points and expanded the scale, likely multiplying Rømer's degrees by 4 to avoid fractions and negative numbers for everyday temperatures.
How does Rømer relate to Celsius?
The relationship is °Rø = °C × 21/40 + 7.5.
About Delisle (°De)
What are the freezing and boiling points of water in Delisle?
Water boils at 0 °De and freezes at 150 °De. Note that the scale is inverted compared to Celsius or Fahrenheit.
Why does the Delisle scale decrease with increasing temperature?
Delisle set the boiling point of water as his zero reference and measured the contraction of mercury as it cooled, leading to higher numbers for colder temperatures.
How does Delisle relate to Celsius?
The relationship is °De = (100 - °C) × 3/2.