Millimeter to Centimeter Converter
Convert millimeters to centimeters with our free online length converter.
Quick Answer
1 Millimeter = 0.1 centimeters
Formula: Millimeter × conversion factor = Centimeter
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.
Millimeter to Centimeter Calculator
How to Use the Millimeter to Centimeter Calculator:
- Enter the value you want to convert in the 'From' field (Millimeter).
- The converted value in Centimeter will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Millimeter to Centimeter: Step-by-Step Guide
Converting Millimeter to Centimeter involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Millimeter = 0.1 centimetersExample Calculation:
Convert 10 millimeters: 10 × 0.1 = 1 centimeters
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 length units?
View all Length conversions →What is a Millimeter and a Centimeter?
The millimeter (symbol: mm) is a unit of length in the metric system equal to one-thousandth of a meter (1/1,000 m) or one-tenth of a centimeter (1/10 cm). It is used for precise measurements in engineering, manufacturing, and everyday applications.
Key relationships:
- 1 millimeter = 0.001 meters (m)
- 1 millimeter = 0.1 centimeters (cm)
- 10 millimeters = 1 centimeter
- 1,000 millimeters = 1 meter
- 1 millimeter ≈ 0.03937 inches (about 1/25th inch)
- 25.4 millimeters = 1 inch (exactly)
The prefix "milli-":
- From Latin "mille" meaning "thousand"
- SI prefix denoting 10⁻³ (one-thousandth)
- Also used in: milligram (mg), milliliter (mL), millisecond (ms)
Visual perspective (how big is it?):
- 1 mm = Thickness of a credit card
- 2 mm = Thickness of a US dime
- 5 mm = Thickness of a pencil lead (mechanical)
- 10 mm = Width of an adult fingernail
- 25.4 mm = Exactly one inch
Convert between length units: mm converter
The centimeter (symbol: cm) is a unit of length equal to exactly one-hundredth of a meter (1/100 m or 0.01 m). It's also equal to exactly 10 millimeters.
The centimeter is part of the International System of Units (SI) and uses the metric prefix "centi-" meaning one-hundredth (from Latin centum, "hundred").
Mathematical Relationships
1 centimeter equals:
- 10 millimeters (mm)
- 0.01 meters (m)
- 0.00001 kilometers (km)
- 0.393701 inches (in)
- 0.0328084 feet (ft)
Key conversion:
- 1 inch = 2.54 cm exactly (this is the official international definition established in 1959)
Why Centimeters?
While the meter is the official SI base unit for length, centimeters are more practical for everyday measurements:
Too small for meters, too large for millimeters: A person who is 1.75 meters tall is more commonly described as 175 centimeters in metric countries. Writing "1.75 m" requires decimals; "175 cm" uses whole numbers.
Human-scale convenience: Most objects people interact with daily—clothing, screens, body measurements, food items—fall naturally into the 1-100 cm range.
Avoids decimal confusion: "15.2 cm" is clearer than "0.152 m" for most people.
Note: The Millimeter is part of the metric (SI) system, primarily used globally in science and trade. The Centimeter belongs to the metric (SI) system.
History of the Millimeter and Centimeter
-
Metric System Origins: The millimeter was defined as a subunit of the meter when the metric system was established in France during the late 18th century (1790s). As measurement standardization progressed, the need for decimal subdivisions of the meter became clear.
-
Industrial Revolution: The millimeter became essential during the 19th century Industrial Revolution as:
- Precision machining required fine tolerances
- Interchangeable parts manufacturing emerged
- Engineering drawings needed standard units
- Technical specifications became international
-
Engineering Adoption: By the mid-19th century, engineers and machinists worldwide adopted millimeters as the standard for:
- Machine tool specifications
- Tolerance requirements (±0.1 mm common)
- Technical drawing dimensions
- Quality control measurements
-
Scientific Standardization: The millimeter became standard in scientific research for:
- Laboratory equipment calibration
- Microscopy measurements
- Specimen documentation
- Experimental apparatus dimensions
-
SI Formalization: When the International System of Units (SI) was established in 1960, the millimeter was confirmed as an official subdivision of the meter, forming part of the coherent decimal system.
-
Modern Manufacturing: The 20th century saw millimeters become universal in:
- Automotive engineering specifications
- Electronics manufacturing (PCB design)
- Aerospace tolerances
- Medical device specifications
- Consumer product dimensions
-
Global Standard: Today, millimeters are the primary unit for precision measurements in virtually every country except the United States (which uses both mm and inches). Even in the US, many technical fields have adopted millimeters as standard.
French Revolution and the Birth of the Metric System
1790s: Revolutionary Innovation: The centimeter was born from the French Revolution's ambition to create a rational, universal measurement system based on nature and decimal mathematics.
The Meter Foundation: In 1791, the French Academy of Sciences defined the meter as one ten-millionth (1/10,000,000) of the distance from the equator to the North Pole along the meridian passing through Paris. The centimeter automatically followed as 1/100 of this meter.
Latin Roots: The prefix "centi-" derives from the Latin centum (hundred), making "centimeter" literally "hundredth of a meter."
1795 Official Adoption: France officially adopted the metric system on April 7, 1795, including the centimeter as a standard subdivision of the meter.
CGS System: The Centimeter's Scientific Era
1874: The Centimeter-Gram-Second System: British scientists James Clerk Maxwell and William Thomson (Lord Kelvin) promoted the CGS system, which used:
- Centimeter for length (instead of meter)
- Gram for mass (instead of kilogram)
- Second for time
Scientific Dominance: The CGS system became the preferred standard for physics and chemistry throughout the late 19th and early 20th centuries. Many scientific formulas and units were developed using centimeters.
Legacy Units: Several units still reflect the CGS heritage:
- Poise (viscosity): measured in gram/(centimeter·second)
- Erg (energy): gram·centimeter²/second²
- Gauss (magnetic field): CGS unit for magnetic flux density
Transition to SI and the Modern Era
1960: The SI System: The International System of Units (SI) was officially established, promoting the meter-kilogram-second (MKS) system instead of CGS.
Centimeter's Continued Relevance: Despite the official SI preference for meters, centimeters remained dominant for everyday measurements because:
- They're more practical for human-scale objects
- They avoid decimals for most common measurements
- They're familiar and intuitive
Global Adoption: Today, 195 of 198 countries use the metric system, with centimeters as the standard for body height, clothing, and everyday measurements. Only the United States, Myanmar, and Liberia officially use non-metric systems.
Common Uses and Applications: millimeters vs centimeters
Explore the typical applications for both Millimeter (metric) and Centimeter (metric) to understand their common contexts.
Common Uses for millimeters
The millimeter is the standard unit for precise measurements across multiple fields:
Engineering & Machining
Precise measurement requirements for manufacturing, quality control, and technical specifications. Essential for maintaining tolerances in mechanical parts.
Why millimeters in engineering:
- Decimal system (easy calculations)
- International standard (ISO)
- Suitable precision range
- Compatible with CNC machinery
- Standard drawing units
Applications:
- Machine tool specifications
- Part tolerances (±0.05 mm common)
- Technical drawing dimensions
- CAD/CAM software units
- Quality inspection reports
Convert for technical work: mm to inches | mm to cm
Technical Design & Drafting
Standard measurement unit for architectural, mechanical, and technical drawings worldwide.
Drawing Standards:
- ISO standards use millimeters
- Engineering drawings in mm
- Architecture plans (many countries)
- Product design specifications
- Patent drawings (international)
Why mm for drawings:
- Eliminates fractions (unlike inches)
- Scales easily (1:10, 1:100, etc.)
- International communication
- CAD software standard
Electronics & PCB Design
Measuring component sizes, trace widths, and circuit board dimensions in electronic manufacturing.
PCB Design:
- Trace width: 0.25-1 mm
- Component footprints: mm specifications
- Hole diameters: 0.6-1.2 mm
- Board thickness: 1.6 mm standard
- Component spacing: mm grid
Component Specs:
- All modern ICs specified in mm
- Resistor/capacitor sizes (mm codes)
- Connector dimensions
- Display module sizes
Meteorology & Climate
Measuring rainfall amounts with precision, essential for weather forecasting, agriculture, and climate research.
Rain Gauges:
- Standard measurement unit worldwide
- Collected in graduated cylinders (mm scale)
- Automated weather stations use mm
- Historical records in mm
- Climate data standardized
Importance:
- Drought assessment
- Flood prediction
- Agricultural planning
- Water resource management
- Climate change tracking
Use our mm converter for scientific calculations.
Manufacturing & Quality Control
Inspecting product dimensions and ensuring parts meet specifications within required tolerances.
QC Measurements:
- Caliper readings in mm
- Micrometer measurements
- Coordinate measuring machines (CMM)
- Surface profile measurements
- Dimensional inspection reports
Industries:
- Automotive parts
- Aerospace components
- Medical devices
- Consumer electronics
- Precision instruments
Jewelry & Watchmaking
Specifying sizes of gems, watch cases, and jewelry components with precision.
Why jewelers use mm:
- International gem standard
- Precise size communication
- Watch industry standard
- Setting specifications
- Customer communication
Measurements:
- Gemstone dimensions
- Ring widths and thicknesses
- Watch case diameters
- Bracelet link sizes
- Clasp dimensions
Medical Measurements
Documenting precise measurements in diagnostics, surgery planning, and treatment monitoring.
Clinical Uses:
- Imaging measurements (CT, MRI, X-ray)
- Tumor size tracking
- Surgical planning
- Needle specifications
- Medical device dimensions
Why mm in medicine:
- International standard
- Appropriate precision
- Imaging system default
- Research compatibility
- Treatment standardization
When to Use centimeters
Medical and Healthcare
Growth Charts: Children's height is tracked in centimeters from birth:
- Pediatricians plot growth on percentile charts
- Birth length recorded in cm (typically 45-55 cm)
- Annual height measurements track development
Medical Measurements:
- Wound size: "3 cm laceration"
- Tumor diameter: measured in cm for staging
- Organ size: "enlarged liver extending 4 cm below rib cage"
- Dilation during childbirth: measured in cm (0-10 cm)
Medical Equipment:
- Blood pressure cuff width: 12-13 cm for adults
- Surgical incision length: documented in cm
- Catheter diameter: measured in mm, length in cm
Education and School Supplies
Rulers and Measuring Tools: Most rulers worldwide show centimeters:
- Standard ruler: 15 cm or 30 cm length
- Meter stick: 100 cm with cm markings
- Tape measures: marked in cm (and meters)
Paper Sizes (International ISO 216 Standard):
- A4 paper: 21 × 29.7 cm (most common worldwide)
- A5 paper: 14.8 × 21 cm (half of A4)
- A3 paper: 29.7 × 42 cm (double A4)
- Letter size (US): 21.6 × 27.9 cm (8.5 × 11 inches)
School Supplies:
- Pencil length: 19 cm (new)
- Notebook width: 15-21 cm
- Eraser length: 4-6 cm
Construction and Home Improvement
Tile Sizes: Floor and wall tiles measured in cm:
- Small tiles: 10×10 cm
- Medium tiles: 30×30 cm
- Large format tiles: 60×60 cm or 80×80 cm
- Subway tiles: 7.5×15 cm
Furniture Dimensions:
- Coffee table height: 40-50 cm
- Dining table height: 75 cm (standard)
- Chair seat height: 45-50 cm
- Sofa seat depth: 50-60 cm
Door Measurements:
- Standard interior door width: 80-90 cm
- Standard door height: 200-210 cm
- Door thickness: 3.5-4.5 cm
Art, Design, and Photography
Photo Print Sizes:
- 10×15 cm (4×6 inches) - standard print
- 13×18 cm (5×7 inches)
- 20×25 cm (8×10 inches)
- 30×40 cm (12×16 inches)
Canvas and Frame Sizes: Art supply stores sell in metric:
- Small canvas: 20×25 cm
- Medium canvas: 30×40 cm
- Large canvas: 50×70 cm
Drawing and Design:
- Technical drawings: dimensioned in cm or mm
- Graph paper: 0.5 cm or 1 cm grids
- Architectural scales: often use 1:50 or 1:100 (cm-based)
Sports and Recreation
Swimming Pool Depth: Measured in cm or meters:
- Shallow end: 90-120 cm
- Deep end: 180-300 cm
- Competition pool depth: minimum 200 cm
Bicycle Frame Sizes: Road bikes measured in cm:
- Small frame: 48-52 cm
- Medium frame: 54-56 cm
- Large frame: 58-62 cm
Sports Equipment:
- Tennis ball diameter: 6.5-6.7 cm
- Golf ball diameter: 4.3 cm
- Basketball diameter: 24 cm
Additional Unit Information
About Millimeter (mm)
How many millimeters are in a centimeter?
There are exactly 10 millimeters (mm) in 1 centimeter (cm).
Conversion:
- 1 cm = 10 mm
- To convert cm to mm: multiply by 10
- To convert mm to cm: divide by 10
Examples:
- 5 cm = 50 mm
- 2.5 cm = 25 mm
- 75 mm = 7.5 cm
Memory aid: "Centi-" means 1/100 meter, "milli-" means 1/1,000 meter, so 10 mm = 1 cm.
Use our cm to mm converter for instant conversions.
How many millimeters are in a meter?
There are exactly 1,000 millimeters (mm) in 1 meter (m).
Conversion:
- 1 m = 1,000 mm
- To convert m to mm: multiply by 1,000
- To convert mm to m: divide by 1,000
Examples:
- 0.5 m = 500 mm
- 1.5 m = 1,500 mm
- 2,750 mm = 2.75 m
Remember: "Milli-" means one-thousandth, so it takes 1,000 mm to make 1 meter.
Convert: mm to meters | meters to mm
What does 'milli' mean in millimeter?
The prefix 'milli-' denotes one-thousandth (1/1,000).
Meaning:
- Comes from Latin "mille" meaning "thousand"
- In metric system: milli- = 10⁻³ = 1/1,000
- 1 millimeter = 1/1,000 of a meter = 0.001 m
Other "milli-" units:
- Milligram (mg) = 1/1,000 gram
- Milliliter (mL) = 1/1,000 liter
- Millisecond (ms) = 1/1,000 second
- Milliamp (mA) = 1/1,000 ampere
Pattern: Always divide by 1,000 to get the base unit.
How thick is 1 millimeter?
1 millimeter is very thin - about the thickness of:
Common objects:
- Credit card: 0.76 mm (slightly thinner)
- US dime: 1.35 mm (slightly thicker)
- 10 sheets of paper: ~1 mm
- Paperclip wire: ~1 mm diameter
- Mechanical pencil lead (0.7mm): Slightly thinner
Visual comparison:
- Thinner than a US penny (1.55 mm)
- About 1/25th of an inch (0.04 inches)
- 10 millimeters = 1 cm = width of fingernail
To visualize: Look at the edge of a credit card - that's less than 1 mm.
How many mm in an inch?
1 inch = 25.4 millimeters exactly (by international agreement).
This is a defined conversion (not an approximation):
- 1 inch ≡ 25.4 mm (exact)
- 1 mm = 1/25.4 inch ≈ 0.03937 inches
Common conversions:
- 1 inch = 25.4 mm
- 2 inches = 50.8 mm
- 3 inches = 76.2 mm
- 4 inches = 101.6 mm
- 12 inches (1 foot) = 304.8 mm
Reverse examples:
- 10 mm ≈ 0.394 inches
- 25 mm ≈ 0.984 inches (almost 1 inch)
- 50 mm ≈ 1.969 inches (almost 2 inches)
Memory trick: 25 mm is almost 1 inch (close enough for quick estimates).
Use our inch to mm converter for precise conversions.
What is 10mm in real life?
10 millimeters = 1 centimeter - about the width of an adult fingernail.
Common 10mm objects:
- Fingernail width (adult index finger)
- AA battery diameter: 14 mm (close)
- Small marble: ~10-15 mm diameter
- M10 bolt diameter: 10 mm
- Thick cardboard: ~10 mm
Comparisons:
- Just under 0.4 inches (0.394 inches exactly)
- Thickness of 100 sheets of paper
- About 3/8 inch (slightly larger)
In measurements:
- Camera/phone thickness: Often 7-10 mm
- Watch case thickness: Often 10-12 mm
- Pencil diameter: ~7-8 mm (10mm would be thick)
How do you read a metric ruler?
Metric rulers are divided into centimeters (cm) and millimeters (mm):
Reading steps:
- Large numbers: Centimeters (0, 1, 2, 3...)
- Long lines: Each centimeter mark
- Short lines: Millimeters (10 per cm)
- Count: From zero to your measurement point
Example reading:
- Between 3 and 4 cm, at the 7th small line = 3.7 cm or 37 mm
- At the 15th cm mark = 15 cm or 150 mm
Tips:
- 10 small marks = 1 cm
- Each small mark = 1 mm
- Halfway between cm marks = 5 mm
- Read to nearest 0.5 mm for precision
Reporting:
- Small objects: Use mm (e.g., "15 mm")
- Larger objects: Use cm (e.g., "15.5 cm")
- Both are correct, choose clearer one
What tools measure millimeters?
Many tools measure in millimeters:
Hand Tools:
- Metric ruler: Basic measurement to 1 mm
- Metric tape measure: Construction/carpentry
- Caliper: Precision to 0.01 mm (digital/vernier)
- Micrometer: Very precise, to 0.001 mm
- Depth gauge: Measuring depths and heights
Digital Tools:
- Digital caliper: Easy reading, 0.01 mm precision
- Laser distance meter: Millimeter accuracy
- Height gauge: Vertical measurements
- Coordinate measuring machine (CMM): Industrial precision
Specialized Tools:
- Feeler gauge: Thin strips in mm thicknesses
- Thread gauge: Checking thread pitch (mm)
- Bore gauge: Internal diameter measurement
- Pin gauge: Precision hole measurement
Which to use:
- Ruler: General purpose (±0.5 mm)
- Caliper: Precision work (±0.01 mm)
- Micrometer: Very tight tolerances (±0.001 mm)
Is mm smaller than cm?
Yes, millimeters (mm) are smaller than centimeters (cm).
Relationship:
- 1 cm = 10 mm
- 1 mm = 0.1 cm
- Millimeter is 10 times smaller than centimeter
Scale comparison:
- Largest: meter (m)
- Middle: centimeter (cm) = 1/100 m
- Smallest: millimeter (mm) = 1/1,000 m
Visual:
- Width of fingernail: 1 cm = 10 mm
- Thickness of dime: 1.35 mm (can't easily express in cm)
When to use each:
- Use mm: Small, precise measurements (< 100 mm)
- Use cm: Medium measurements (1-100 cm)
- Use m: Large measurements (> 1 meter)
Example:
- Pencil length: 19 cm or 190 mm (19 cm clearer)
- Wire diameter: 2 mm (not 0.2 cm - awkward)
How much rain is 1mm?
1 millimeter of rain means 1 mm depth of water would cover a flat surface if none drained away.
What it means:
- 1 mm rain = 1 liter per square meter of water
- Light drizzle might produce 1-2 mm/hour
- Barely enough to wet the ground thoroughly
Rain intensity scale:
- Trace-1 mm: Very light drizzle
- 1-2 mm: Light rain
- 2-5 mm: Light to moderate rain
- 5-10 mm: Moderate rain
- 10-20 mm: Heavy rain
- 20-50 mm: Very heavy rain
- >50 mm: Extreme rainfall (per hour)
Practical impact:
- 1 mm: Barely wets surfaces
- 10 mm: Significant watering
- 25 mm: Heavy rain event
- 100 mm: Major storm (in 24 hours)
Measurement:
- Rain gauge collects water
- Depth measured in mm
- Standard worldwide for weather reporting
Conversion Table: Millimeter to Centimeter
| Millimeter (mm) | Centimeter (cm) |
|---|---|
| 0.5 | 0.05 |
| 1 | 0.1 |
| 1.5 | 0.15 |
| 2 | 0.2 |
| 5 | 0.5 |
| 10 | 1 |
| 25 | 2.5 |
| 50 | 5 |
| 100 | 10 |
| 250 | 25 |
| 500 | 50 |
| 1,000 | 100 |
People Also Ask
How do I convert Millimeter to Centimeter?
To convert Millimeter to Centimeter, enter the value in Millimeter in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our length converter page to convert between other units in this category.
Learn more →What is the conversion factor from Millimeter to Centimeter?
The conversion factor depends on the specific relationship between Millimeter and Centimeter. 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 Centimeter back to Millimeter?
Yes! You can easily convert Centimeter back to Millimeter by using the swap button (⇌) in the calculator above, or by visiting our Centimeter to Millimeter converter page. You can also explore other length conversions on our category page.
Learn more →What are common uses for Millimeter and Centimeter?
Millimeter and Centimeter are both standard units used in length measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our length converter for more conversion options.
For more length conversion questions, visit our FAQ page or explore our conversion guides.
Helpful Conversion Guides
Learn more about unit conversion with our comprehensive guides:
📚 How to Convert Units
Step-by-step guide to unit conversion with practical examples.
🔢 Conversion Formulas
Essential formulas for length and other conversions.
⚖️ Metric vs Imperial
Understand the differences between measurement systems.
⚠️ Common Mistakes
Learn about frequent errors and how to avoid them.
All Length Conversions
Metric Prefix Guide
Understanding Metric Prefixes
The metric system uses standard prefixes to indicate multiples or fractions of base units. For example, converting from millimeter to centimeter involves a multiplication factor of 1000.
| Prefix | Symbol | Power | Multiplier | Example |
|---|---|---|---|---|
| deca | da | 10¹ | 10 | decagram (dag) |
| (base) | 10⁰ | 1 | meter (m) | |
| deci | d | 10⁻¹ | 0.1 | decigram (dg) |
| centi | c | 10⁻² | 0.01 | centigram (cg) |
| milli | m | 10⁻³ | 0.001 | milligram (mg) |
| micro | μ | 10⁻⁶ | 0.000001 | microgram (μg) |
| nano | n | 10⁻⁹ | 0.000000001 | nanogram (ng) |
| pico | p | 10⁻¹² | 0.000000000001 | picogram (pg) |
Note: To convert between prefixed units, multiply or divide by powers of 10. For conversions betweenmillimeter and centimeter, divide by 1000.
Other Length Units and Conversions
Explore other length units and their conversion options:
- Meter (m) • Millimeter to Meter
- Kilometer (km) • Millimeter to Kilometer
- Hectometer (hm) • Millimeter to Hectometer
- Decimeter (dm) • Millimeter to Decimeter
- Inch (in) • Millimeter to Inch
- Foot (ft) • Millimeter to Foot
- Yard (yd) • Millimeter to Yard
- Mile (mi) • Millimeter to Mile
- Nautical Mile (NM) • Millimeter to Nautical Mile
- Micrometer (μm) • Millimeter to Micrometer
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 — Official US standards for length measurements
Bureau International des Poids et Mesures — International System of Units official documentation
Last verified: December 3, 2025