Your result will appear here
Fill in the fields and press Calculate.
Centimetres and inches measure the same thing in two systems — metric and imperial — so switching between them is a fixed multiplication. Whether you're reading a screen size, a piece of furniture or a clothing measurement, this converter turns centimetres into inches and back in one step.
cm to Inches Converter: step-by-step worked example
What is a 81 cm waist in inches (jeans size)?
- Value
- 81
- Direction
- Centimetres → Inches
- 1
Conversion factor (definition)
1 in = 2.54 cm exactly — fixed by the 1959 International Yard and Pound Agreement
1 in = 2.54 cm = 2.54 cm
- 2
Inverse factor
1 cm = 1 ÷ 2.54 in
1 ÷ 2.54 = 0.3937 in
- 3
Conversion
in → cm: × 2.54 · cm → in: ÷ 2.54
81 cm ÷ 2.54 = 31.8898 in
- 4
Check (reverse direction)
Convert the result back with the inverse operation
31.8898 in × 2.54 = 81.0001 cm
- in31.8898
- cm81
- mm810
- ft2.6575
Good to know: Screen size is the diagonal, not the width: a 55-inch (139.7 cm) 16:9 TV is about 121.8 × 68.5 cm. Check the width when fitting it to a wall or stand.
cm to Inches Converter — how it works
The conversion factor
The relationship is exact and defined: 1 inch = 2.54 centimetres.
| To convert | Do this |
|---|---|
| cm → inches | divide by 2.54 |
| inches → cm | multiply by 2.54 |
Common values
| Centimetres | Inches |
|---|---|
| 1 cm | 0.39 in |
| 10 cm | 3.94 in |
| 30 cm | 11.81 in |
| 100 cm | 39.37 in |
Worked example
A 152 cm height converts to 152 ÷ 2.54 = 59.84 inches, which is about 4 feet 11.8 inches. Going the other way, a 32-inch waist is 32 × 2.54 = 81.3 cm.
Inches to centimetres table
| Inches | Centimetres |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 3 | 7.62 |
| 4 | 10.16 |
| 5 | 12.7 |
| 6 | 15.24 |
| 7 | 17.78 |
| 8 | 20.32 |
| 9 | 22.86 |
| 10 | 25.4 |
| 11 | 27.94 |
| 12 | 30.48 |
| 13 | 33.02 |
| 14 | 35.56 |
| 15 | 38.1 |
| 17 | 43.18 |
| 19 | 48.26 |
| 20 | 50.8 |
| 21.5 | 54.61 |
| 24 | 60.96 |
| 27 | 68.58 |
| 32 | 81.28 |
| 40 | 101.6 |
| 43 | 109.22 |
| 50 | 127 |
| 55 | 139.7 |
| 65 | 165.1 |
Centimetres to inches table
| Centimetres | Inches |
|---|---|
| 1 | 0.39 |
| 5 | 1.97 |
| 10 | 3.94 |
| 15 | 5.91 |
| 20 | 7.87 |
| 25 | 9.84 |
| 30 | 11.81 |
| 50 | 19.69 |
| 75 | 29.53 |
| 100 | 39.37 |
Frequently asked questions
How many inches is 1 cm?+
One centimetre is 0.3937 inches — a little under four tenths of an inch. To convert any number of centimetres to inches, divide by 2.54.
How do I convert cm to inches?+
Divide the centimetre value by 2.54, since 1 inch is defined as exactly 2.54 cm. For example, 50 cm ÷ 2.54 = 19.69 inches.
Is the inch exactly 2.54 cm?+
Yes. Since 1959 the international inch has been defined as exactly 2.54 centimetres, so the conversion is exact, not an approximation.
How do I convert inches back to cm?+
Multiply the inch value by 2.54. A 40-inch TV is 40 × 2.54 = 101.6 cm wide diagonally.
What is 100 cm in inches?+
100 cm is 39.37 inches, or about 3 feet 3.4 inches. One metre is just under 3 feet 3.5 inches.
About this page
- Publisher:
- Kalkoro — Teknolojig Bilişim Teknolojileri A.Ş., İstanbul
- Written by:
- Ahmet Tur — Editor (Math, date & time, unit conversion, physics & chemistry, everyday tools)
- Reviewed by:
- Kübra Yıldız — Editor
Parameters come from official sources; the last update date is shown at the bottom of the page.
Spotted a wrong result? Use the "Report a bug" button at the top of the page; every report is reviewed.
How we calculate and our accuracy policy →
Results are for information only. For official matters the relevant authority's calculation prevails.
Last updated: