Centimeter is 0.01 meter units.
Centimeters to Inches Converter — cm to in
Convert Centimeter (cm) to Inch (in) using the exact conversion factor (1 centimeter = 0.3937007874 inch). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Centimeters to Inches converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
An inch is exactly 0.0254 meters.
Result = input x 0.01 / 0.0254.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Centimeters to Inches
Centimeter and Inch both measure length. Centimeter is typically associated with standard small-length unit worldwide except the US, while Inch is typically associated with united States and United Kingdom (small measurements, screen sizes, hardware).
Formula
inches = centimeters × 0.393700787402
This factor comes from each unit's defined relationship to the category's base unit: 1 centimeter equals 0.01 base units, and 1 inch equals 0.0254 base units, so dividing one by the other gives the direct centimeter-to-inch factor of 0.393700787402.
Simple example
1 cm × 0.3937007874 = 0.3937007874 in
1 centimeter = 0.3937007874 inches.
Real-world example
10 cm × 0.3937007874 = 3.937007874 in
10 centimeters = 3.937007874 inches.
Conversion table
| Centimeter (cm) | Inch (in) |
|---|---|
| 1 cm | 0.3937007874 in |
| 5 cm | 1.968503937 in |
| 10 cm | 3.937007874 in |
| 21.0975 cm | 8.306102362 in |
| 42.195 cm | 16.61220472 in |
| 100 cm | 39.37007874 in |
Reverse conversion: Inch to Centimeter
0.3937007874 in × 2.54 = 1 cm
0.3937007874 inches = 1 centimeters.
centimeters = inches × 2.54
For a page dedicated to this direction, see Inch to Centimeter.
Centimeter vs. Inch
| Aspect | Centimeter | Inch |
|---|---|---|
| Family | SI derived (metric prefix) unit | US/imperial customary unit |
| Typical use | Everyday small-object and body measurement (height, clothing sizes) outside the US | Screen and display size measurement worldwide (even in metric countries) |
| Where it's used | Standard small-length unit worldwide except the US | United States and United Kingdom (small measurements, screen sizes, hardware) |
Understanding the Centimeter
Centimeter (cm) measures distance. A centimeter is one-hundredth of a meter. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard small-length unit worldwide except the US
Uses of the Centimeter today
- Everyday small-object and body measurement (height, clothing sizes) outside the US
- Construction and manufacturing tolerances internationally
History of the Centimeter
The centimeter follows directly from the meter via the 'centi-' SI prefix (10⁻²), introduced with the metric system in the 1790s.
Historical origin. Centimeter was not the invention of a single named person; it developed through the process described above.
Understanding the Inch
Inch (in) measures distance. The international inch is defined as exactly 25.4 millimeters. It is classified as a US/imperial customary unit.
Where it's used: United States and United Kingdom (small measurements, screen sizes, hardware)
Uses of the Inch today
- Screen and display size measurement worldwide (even in metric countries)
- US/UK small-object and body measurement
- Hardware, tools, and pipe fittings (US)
History of the Inch
The inch traces to medieval England, traditionally defined as the length of three barleycorns, later standardized as 1/12 of a foot. The international inch (exactly 25.4 mm) was fixed by the same 1959 agreement that standardized the foot and yard.
Historical origin. Inch was not the invention of a single named person; it developed through the process described above.
Centimeter — sources
- BIPM SI Brochure — SI prefixes — Defines 'centi-' as the prefix for 10⁻².
Inch — sources
- NIST — International yard and pound (1959) — Fixes the modern inch at exactly 25.4 millimeters.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many inches are in 1 centimeter?
1 centimeter equals 0.3937007874 inches, using the exact defined conversion factor rather than an estimate.
How do I convert centimeter to inch?
Multiply the centimeter value by 0.3937007874. The converter above does this instantly to whatever precision you set.
How do I convert inch back to centimeter?
Use the reverse factor: 1 inch equals 2.54 centimeters. You can also use the swap control in the converter above to flip the direction instantly.
What is a centimeter?
Centimeter (cm) measures distance. A centimeter is one-hundredth of a meter. It is classified as a SI derived (metric prefix) unit.
What is a inch?
Inch (in) measures distance. The international inch is defined as exactly 25.4 millimeters. It is classified as a US/imperial customary unit.
Is the centimeter to inch conversion exact?
Yes. The international inch is defined as exactly 25.4 millimeters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the centimeter still used today?
Standard small-length unit worldwide except the US