Convert Centimeter to Inch
Convert centimeters to inches instantly. 1 centimeter = 0.3937007874 inch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Inch to Centimeter converter for the reverse conversion.
Units explained
Centimeter
A centimeter is a metric unit of length equal to one hundredth of a meter (1/100 m). It is one of the most commonly used SI sub-units in daily life, especially for measuring small objects, body dimensions, paper sizes, and short distances.
The centimeter emerged from the French metric system established by the French Academy of Sciences in 1793. The metric system introduced decimal-based prefixes (milli-, centi-, deci-, deca-, hecto-, kilo-) to create proportional sub-units of the meter.
Centimeters are the standard unit for everyday measurement in nearly every country outside the United States. They are used for body height, clothing sizes, rainfall, paper formats (A4 is 21 × 29.7 cm), screen dimensions, and most consumer product specifications.
Developed in France during the late 18th century as part of the metric system designed by the French Academy of Sciences. Formally adopted in France in 1795 and ratified internationally through the Metre Convention signed in Paris in 1875.
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
Centimeter to Inch conversion formula
The relationship between centimeters and inches:
To convert centimeters to inches, multiply the value in centimeters by 0.3937007874. To reverse, multiply inches by 2.54.
How to use this converter
Type a value into the calculator. The result in inches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Inch to Centimeter converter for the reverse direction.
Step-by-step: convert centimeters to inches
- Write down the value in centimeters (cm).
- Multiply that value by the factor 0.3937007874.
- The product is the equivalent value in inches (in).
- To reverse, multiply the inch value by 2.54.
Worked examples
Example 1 — Convert 1 cm to in:
1 × 0.3937007874 = 0.3937007874 in
Example 2 — Convert 100 cm to in:
100 × 0.3937007874 = 39.3700787402 in
Real-world example — TV diagonal in centimeters
A 140-cm TV screen diagonal equals about 55 inches. European retailers quote screen sizes in centimeters; brand-name TV models reference the same screen as a 55-inch product. Converting centimeters to inches lets you match the spec.
140 cm × 0.3937007874 = 55.1181102362 in
Real-world example — A4 paper width
A4 paper is 21 cm wide, equivalent to 8.27 inches. The conversion comes up every time someone formats an A4 document for a printer that wants page sizes in inches — page-setup dialogue boxes mix the two units constantly.
21 cm × 0.3937007874 = 8.2677165354 in
Real-world example — Centimeter ruler to inch equivalents
A 30-cm school ruler is about 11.81 inches long. Travellers buying stationery abroad calibrate by feel: a centimeter ruler is just a touch shorter than the foot-long imperial ruler they grew up with.
30 cm × 0.3937007874 = 11.811023622 in
Centimeter to Inch conversion table
Standard reference values for converting centimeters to inches:
| Centimeter [cm] | Inch [in] |
|---|---|
| 0.01 | 0.0039370079 |
| 0.1 | 0.0393700787 |
| 1 | 0.3937007874 |
| 2 | 0.7874015748 |
| 3 | 1.1811023622 |
| 4 | 1.5748031496 |
| 5 | 1.968503937 |
| 10 | 3.937007874 |
| 20 | 7.874015748 |
| 30 | 11.811023622 |
| 40 | 15.7480314961 |
| 50 | 19.6850393701 |
| 100 | 39.3700787402 |
| 500 | 196.8503937008 |
| 1000 | 393.7007874016 |
Frequently asked questions
How many inches is 1 centimeter?
How do I convert centimeters to inches?
How do I convert inches back to centimeters?
How many inches is 100 centimeters?
Popular length unit conversions
Convert Centimeter to other length units
Show all Centimeter conversions
Metric / SI (17 units)
Imperial / US Customary (27 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)
Sources & references
Conversion factor (1 cm = 0.3937007874 in) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.