Centimeter to Inch (cm to in)
Result
0.3937007874 Inch
Formula
in = cm × 0.3937007874
1 cm = 0.3937007874 in, and 1 in = 2.54 cm.
The metre is the SI base unit, defined by the speed of light. Since the 1959 international yard and pound agreement the imperial and US customary units are defined exactly in metres: 1 yard = 0.9144 m, so 1 foot = 0.3048 m, 1 inch = 2.54 cm and 1 mile = 1,609.344 m.
Worked examples
- 1 cm × 0.3937007874 = 0.39370079 in
- 30 cm × 0.3937007874 = 11.811024 in
- 100 cm × 0.3937007874 = 39.370079 in
- 170 cm × 0.3937007874 = 66.929134 in
Things to know about cm to in
- Divide by 2.54. For heights, split the result into feet and inches: 170 cm = 66.93 in = 5 ft 6.9 in.
- A 30 cm ruler is 11.81 in, a little short of a foot.
Centimeter to Inch table
| Centimeter (cm) | Inch (in) |
|---|---|
| 1 | 0.39370079 |
| 2 | 0.78740157 |
| 5 | 1.9685039 |
| 10 | 3.9370079 |
| 20 | 7.8740157 |
| 30 | 11.811024 |
| 50 | 19.685039 |
| 100 | 39.370079 |
| 170 | 66.929134 |
| 1,000 | 393.70079 |
The units
- Centimeter (cm)
- One hundredth of a metre (0.01 m). Common for body height and clothing sizes.
- Inch (in)
- Exactly 2.54 cm by the 1959 international agreement; 12 inches make a foot.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy