cm to Inches Converter
1 centimetre = 0.3937 inches.
Enter a value
Result
1 centimetres =
0.393701 in
1 × 0.393701 = 0.393701
1 inch = 2.54 cm exactly · 1 mile = 1.609344 km exactly
Show the working
- 1. Convert 1 cm to metres: 1 × 0.01 = 0.01.
- 2. Convert to in: 0.01 ÷ 0.0254 = 0.393701.
1 cm in every unit
Handy reference lengths
- A4 sheet (long side)
- 29.7 cm
- Standard door height
- 2.03 m
- Football pitch
- 105 m
- Marathon
- 42.195 km
Conversion table
Centimetres to Inches
| Centimetres | Inches |
|---|---|
| 1 | 0.3937 |
| 2 | 0.7874 |
| 5 | 1.9685 |
| 10 | 3.937 |
| 15 | 5.9055 |
| 20 | 7.874 |
| 25 | 9.8425 |
| 30 | 11.811 |
| 50 | 19.685 |
| 75 | 29.528 |
| 100 | 39.37 |
| 150 | 59.055 |
| 200 | 78.74 |
| 250 | 98.425 |
| 500 | 196.85 |
Inches to Centimetres
| Inches | Centimetres |
|---|---|
| 1 | 2.54 |
| 2 | 5.08 |
| 5 | 12.7 |
| 10 | 25.4 |
| 15 | 38.1 |
| 20 | 50.8 |
| 25 | 63.5 |
| 30 | 76.2 |
| 50 | 127 |
| 75 | 190.5 |
| 100 | 254 |
| 150 | 381 |
| 200 | 508 |
| 250 | 635 |
| 500 | 1,270 |
Formula and worked example
inches = centimetres ÷ 2.54 (because 1 inch = 2.54 cm exactly, fixed by international agreement in 1959).
Convert 30 cm to inches: 30 ÷ 2.54 = 11.811 inches — the diagonal of a standard A4 sheet’s short side is close to this.
When you need this
Screen and tire sizes are still sold in inches while most of the world measures in centimetres, so shopping lists for monitors, TVs and bike frames cross the two constantly. Sewing patterns mix them too: seam allowances in inches, body measurements in cm. This page keeps both honest to the exact 2.54 cm definition.
Questions people ask
How many inches is 1 cm?
0.3937 inches — divide centimetres by 2.54.
How many cm in an inch?
Exactly 2.54 cm, fixed by the 1959 international yard and pound agreement.
Is 5 cm 2 inches?
Almost — 5 cm is 1.9685 inches, just under 2.
How do I convert cm to feet?
Divide cm by 30.48; the Height Converter breaks it into feet and inches.
Why 2.54 exactly?
The inch was redefined in 1959 so that it equals 25.4 mm exactly, ending centuries of slightly different national inches.
Related conversions
How we calculate this
We use the standard published formula or definition for this calculation, and we show the working so you can check it. Source: NIST Special Publication 811, Guide for the Use of the International System of Units.
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