Inch to Centimeter (in to cm)
Result
2.54 Centimeter
Formula
cm = in × 2.54
1 in = 2.54 cm, and 1 cm = 0.3937007874 in.
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 in × 2.54 = 2.54 cm
- 6 in × 2.54 = 15.24 cm
- 12 in × 2.54 = 30.48 cm
- 65 in × 2.54 = 165.1 cm
Things to know about in to cm
- One inch is exactly 2.54 cm by definition, so these results are exact.
- Screen sizes are measured on the diagonal: a 65-inch TV is 165.1 cm corner to corner, not wide.
- Nominal sizes such as bicycle wheels ("29-inch") and pipe sizes are names, not exact measurements.
Inch to Centimeter table
| Inch (in) | Centimeter (cm) |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 5 | 12.7 |
| 6 | 15.24 |
| 10 | 25.4 |
| 12 | 30.48 |
| 20 | 50.8 |
| 50 | 127 |
| 65 | 165.1 |
| 100 | 254 |
| 1,000 | 2,540 |
The units
- Inch (in)
- Exactly 2.54 cm by the 1959 international agreement; 12 inches make a foot.
- Centimeter (cm)
- One hundredth of a metre (0.01 m). Common for body height and clothing sizes.
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