Inches to Centimeters Converter
Enter the length in inches below to convert it to centimeters.
Convert Inches to Centimeters
Enter a value in inches (in) to convert to centimeters (cm).
Inches to Centimeters Conversion Chart (1–40 Continuous)
Continuous 1 to 40 inches lookup table with exact decimals and reduced nearest 1/64 fractions. Highlighted rows mark common shop and ruler values.
| Inches (in) | Decimal (cm) | Fraction — Nearest 1/64 (Reduced) | Nearest 1/16 (Tape) |
|---|---|---|---|
1 in★ Common | 2.54 cm | 2 35/64 cm | 2 9/16 cm |
2 in★ Common | 5.08 cm | 5 5/64 cm | 5 1/16 cm |
3 in★ Common | 7.62 cm | 7 5/8 cm | 7 5/8 cm |
4 in | 10.16 cm | 10 5/32 cm | 10 3/16 cm |
5 in★ Common | 12.7 cm | 12 45/64 cm | 12 11/16 cm |
6 in★ Common | 15.24 cm | 15 15/64 cm | 15 1/4 cm |
7 in | 17.78 cm | 17 25/32 cm | 17 3/4 cm |
8 in★ Common | 20.32 cm | 20 5/16 cm | 20 5/16 cm |
9 in | 22.86 cm | 22 55/64 cm | 22 7/8 cm |
10 in★ Common | 25.4 cm | 25 13/32 cm | 25 3/8 cm |
11 in | 27.94 cm | 27 15/16 cm | 27 15/16 cm |
12 in★ Common | 30.48 cm | 30 31/64 cm | 30 1/2 cm |
How to Convert Inches to Centimeters
To convert inches to centimeters, multiply the length by the following conversion ratio: 2.54 centimeters/inch.
Since one inch is equal to 2.54 centimeters, you can use this simple formula to convert:
The length in centimeters is equal to the length in inches multiplied by 2.54.
For example, here's how to convert 10 inches to centimeters using the formula above.
How Many Centimeters Are in an Inch?
There are 2.54 centimeters in an inch, which is why we use this value in the formula above.
Our inch fraction and decimal calculator can convert inches and centimeters, and it automatically converts the results to US customary, imperial, and SI metric values.
Inches and centimeters are both units used to measure length. Keep reading to learn more about each unit.
How to Convert Inches to Fractional Inches (1/16″, 1/32″ & 1/64″)
Plain-language method for turning decimal inches into a standard tape-measure or machinist ruler fraction
Calculators give you a decimal number (such as 10 in), but tape measures and woodworking rulers are marked in binary fractions of an inch—most commonly 1/16″ on carpenter tapes, 1/32″ on fine woodworking rules, and 1/64″ on machinist scales.
Here is the step-by-step worked example for converting 10 inches (in) into fractional inches:
- Find the decimal inches result: Convert 10 in to inches to get 10 in.
- Separate the whole inches from the decimal part: Keep the whole number 10 aside, leaving the decimal remainder 0.
- Multiply the decimal part by your desired fraction denominator (16, 32, or 64) and round half up: Multiply 0 by 16, 32, or 64, then round to the nearest whole number (values ending in .5 round up).
- Reduce the fraction to lowest terms: If the rounded top number (numerator) is even, divide both top and bottom by 2 (or their Greatest Common Divisor) until the top number is odd, then combine with your whole inches.
What Is an Inch?
An inch is a unit of length equal to 1/12 of a foot or 1/36 of a yard. Because the international yard is legally defined as exactly 0.9144 meters under the 1959 International Yard and Pound Agreement, one inch equals exactly 2.54 centimeters (25.4 millimeters or 25,400,000 nanometers). [1]
The inch is a US customary and imperial unit of length. Inches can be abbreviated as in; for example, 1 inch can be written as 1 in.
Inches can also be denoted using the ″ symbol, otherwise known as a double prime. Often a double quote (") is used instead of a double prime for convenience. A double prime is commonly used to express 1 in as 1″.
The standard ruler is 12 inches long and is a common tool for measuring a length in inches. Another frequently used tool to perform measurements in inches is a tape measure, which commonly comes in lengths from 6' to 35'. Other devices used to measure in inches include scales, calipers, measuring wheels, micrometers, yardsticks, and even lasers.
What Is a Centimeter?
A centimeter is a metric unit of length equal to one-hundredth (1/100) of a meter, which is the International System of Units (SI) base unit of length. One centimeter is also equal to 10 millimeters or approximately 0.39370079 inches. [2]
The centimeter, or centimetre, is part of the SI metric system used worldwide for everyday, scientific, and clinical measurements. Centimeters can be abbreviated as cm; for example, 1 centimeter can be written as 1 cm.
In the metric system, "centi" is the Latin-derived prefix for hundredths, or 10⁻². Because 1 international inch is legally defined as 2.54 centimeters, converting between centimeters and inches is anchored by an exact mathematical constant.
Centimeters are measured using metric rulers, tailor's measuring tapes, stadiometers (for human height), and vernier calipers across carpentry, apparel sizing, school science, and medical charts.
When converting length between inches (in) and centimeters (cm), keep full floating-point precision (1" = 2.54 cm; 1 cm = 0.3937008 in) during intermediate calculations and round only the final centimeter figure to match your instrument tolerance.
More Inch & Centimeter Conversions
Need to calculate in the opposite direction? Use our centimeters to inches converter (cm to in) to switch your starting unit immediately. You can also explore related tools such as converting feet to centimeters, converting meters to centimeters, or converting inches to millimeters.
Convert from Inches
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Length Metrology Standard — Inches (in) to Centimeters (cm)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Inch (in) & Centimeter (cm)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (in to cm)