cm to Inches Converter

Convert centimeters to inches instantly — 1 cm = 0.3937 inches

Convert

0.3937

1 cm =

0.3937 in

Quick Reference

1 cm0.3937 in

5 cm1.9685 in

10 cm3.937 in

15 cm5.9055 in

20 cm7.874 in

25 cm9.8425 in

30 cm11.811 in

50 cm19.685 in

100 cm39.3701 in

All utility & math

Quick summary

To convert centimeters to inches, divide by 2.54 (or multiply by about 0.393701), because one inch is exactly 2.54 cm. So 1 cm = 0.3937 in, 10 cm = 3.937 in, and 30 cm = 11.811 in. To convert inches to centimeters, multiply by 2.54 — 12 in = 30.48 cm. Use swap to reverse. Runs entirely in your browser.

Reviewed by Simple Calculators TeamLast reviewed July 18, 2026

How to use this calculator

Type the length in centimeters into the cm field.
Read the converted length in the in field and in the large result line below it (shown to up to four decimal places).
To convert inches to centimeters, press the Swap units button between the fields and enter the value in inches.
Use the Quick Reference table for common lengths from 1 to 100 cm.
Press Reset to return to the default of 1 cm.

cm to Inches Formulas

Centimeters to Inches

\text{in} = \frac{\text{cm}}{2.54}

cm: Length in centimeters
in: Length in inches
2.54: Centimeters in one inch (exact by definition)

Worked example

Convert 30 cm to inches

Given: cm = 30
Calculation: $\text{in} = \frac{30}{2.54}$
Result: 30 cm = 11.811 in

Inches to Centimeters

\text{cm} = \text{in} \times 2.54

in: Length in inches
cm: Length in centimeters

Worked example

Convert 12 inches (one foot) to centimeters

Given: in = 12
Calculation: $\text{cm} = 12 \times 2.54$
Result: 12 in = 30.48 cm

Frequently asked questions

How do I convert cm to inches?

Divide the centimeters by 2.54, since one inch is exactly 2.54 cm. For example, 20 cm ÷ 2.54 = 7.874 in, and 50 cm ÷ 2.54 = 19.685 in. Multiplying by 0.393701 gives the same answer. To convert inches to centimeters, multiply by 2.54 instead, or press the swap button in the converter.

How many inches is 1 cm?

One centimeter is about 0.3937 inches, so it takes roughly 2.5 centimeters to make an inch. That means 10 cm is 3.937 in and 100 cm (one meter) is 39.3701 in. Because the inch is defined as exactly 2.54 cm, these figures come from a single division rather than an approximation.

What is 30 cm in inches?

30 cm is 11.811 inches (30 ÷ 2.54), just under the 12 inches of a standard US ruler. A 30 cm ruler, common in metric countries, is therefore about 0.19 in shorter than a foot-long ruler. The Quick Reference table lists this and other common lengths, from 1 to 100 cm.

How do I convert inches to cm?

Multiply the inches by 2.54. For example, 6 in × 2.54 = 15.24 cm, and 12 in (one foot) × 2.54 = 30.48 cm. In the converter, press the swap button so the input field reads inches, then type your measurement to see the result in centimeters.

How tall is 170 cm in feet and inches?

170 cm is 66.9291 inches, which is 5 feet 6.93 inches — about 5 ft 7 in. To split inches into feet, divide by 12: the whole number is feet and the remainder is inches. Likewise, 180 cm is 70.8661 in, or about 5 ft 10.9 in. For heights, the cm to feet converter does this step for you.

Why is an inch exactly 2.54 cm?

Because the inch is defined that way. Under the 1959 international yard and pound agreement, the inch was fixed at exactly 25.4 millimeters (2.54 cm), so converting between the two is exact rather than a measured approximation. Any rounding you see comes only from how many decimal places are displayed.

How many centimeters are in a foot?

There are exactly 30.48 centimeters in a foot, since a foot is 12 inches and each inch is 2.54 cm (12 × 2.54 = 30.48). Going the other way, one meter (100 cm) is about 3.2808 feet, or 39.3701 inches. For feet directly, use the cm to feet converter.

Key terms

Centimeter (cm): A metric length unit; 1 cm = 0.3937 in.
Inch (in): An imperial length unit defined as exactly 2.54 cm.
Conversion Factor: Divide cm by 2.54 to get inches.

Methodology, sources & limitations

This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.

For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.

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