Convert inches to cm instantly
Type any inch measurement into the calculator above and get the exact centimetre value right away — no rounding guesswork, no sign-up required. Whether you are converting a screen size, a clothing measurement, or a DIY dimension, this tool does the maths for you in under a second.
How to use this inches-to-centimetres converter
- Enter the number of inches in the input field above.
- The equivalent value in centimetres (cm) appears instantly.
- Need to go the other way? Flip the direction to convert cm to inches just as easily.
- Copy the result or keep adjusting the number — the page recalculates in real time.
Worked example: converting 6 inches to cm
Imagine you bought a phone with a 6-inch screen and need the measurement in centimetres for a product listing.
- Start with: 6 inches
- Multiply by 2.54 (the exact number of centimetres in one inch)
- 6 × 2.54 = 15.24 cm
So a 6-inch phone screen is 15.24 centimetres across the diagonal.
How the inches to cm calculation works
One inch is defined as exactly 2.54 centimetres — this is a fixed international standard (set by the International Yard and Pound Agreement in 1959), so the conversion is always precise.
The formula in plain words: multiply your inch value by 2.54.
cm = inches × 2.54Reverse it to go from centimetres to inches:
inches = cm ÷ 2.54Quick reference: common inches to cm conversions
| Inches | Centimetres (cm) |
|---|---|
| 1 inch | 2.54 cm |
| 2 inches | 5.08 cm |
| 5 inches | 12.70 cm |
| 10 inches | 25.40 cm |
| 25 inches | 63.50 cm |
| 50 inches | 127.00 cm |
| 100 inches | 254.00 cm |
1 inch = 2.54 cm exactly. The reverse: 1 cm = 0.3937 inches.
Other ways people ask the same question
People phrase this conversion many different ways — here is what they all mean and when each matters:
- "Inches to centimetres" — the standard metric conversion used in science, medicine, and most of the world outside the US.
- "Convert ″ to cm" — the double-prime symbol (″) is just shorthand for inches.
- "Inches to millimetres (mm)" — multiply by 25.4 instead of 2.54 (10 mm = 1 cm).
- "Feet and inches to cm" — convert feet to inches first (1 foot = 12 inches), then multiply the total by 2.54. For example, 5 ft 8 in = 68 inches = 172.72 cm.
- "Imperial to metric length" — a broader phrase covering the same idea when someone is moving between US/UK customary units and the metric system.
Quick tips and common mistakes
- Don't confuse inches and feet. Make sure you are entering inches, not feet. 5.8 inches is very different from 5 feet 8 inches.
- Decimal inches, not fractions. The tool accepts decimals (e.g. 5.5), so convert fractions first: ½ inch = 0.5, ¼ inch = 0.25, ¾ inch = 0.75.
- Watch out for rounding. If you need precision (engineering, 3D printing, tailoring), keep at least two decimal places in your result.
- Ruler markings vary. UK and US rulers both show inches, but European rulers show only centimetres — the same object looks like a different number on each.
- Screen sizes are diagonal. TV and phone sizes quoted in inches refer to the diagonal of the screen, not the width or height.
Everything on this page runs entirely in your browser. No numbers you enter are sent to any server — your data stays private on your device.
Got a length already in centimetres? Flip the converter to go from cm back to inches just as quickly.
Bottom line: one inch is always 2.54 cm — use the calculator above to convert any measurement in seconds, with no rounding worries.