Your result will appear here
Fill in the fields and press Calculate.
Inches and centimetres come from two different measurement systems — the imperial inch and the metric centimetre — and converting between them is a daily need for screen sizes, clothing, height, paper and DIY. The relationship is fixed and exact: one inch is precisely 2.54 centimetres.
Enter a value and pick the direction, and the conversion is done instantly.
Inches to CM Converter: step-by-step worked example
How many centimetres is the diagonal of a 55-inch TV?
- Value
- 55
- Direction
- Inches → Centimetres
- 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
55 in × 2.54 = 139.7 cm
- 4
Check (reverse direction)
Convert the result back with the inverse operation
139.7 cm ÷ 2.54 = 55 in
- in55
- cm139.7
- mm1,397
- ft4.5833
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.
Inches to CM Converter — how it works
The conversion
1 inch = 2.54 cm (exactly, by definition). So: - Inches → cm: multiply by 2.54. - cm → inches: divide by 2.54.
10 inches = 25.4 cm; 180 cm = 70.87 inches.
Where it's used
- Screens: TV and monitor sizes are quoted in inches (a 55-inch TV is 139.7 cm diagonally).
- Height: converting a height between systems (5 ft 11 in = 180.3 cm).
- Clothing and paper: waist sizes, A-series vs letter dimensions.
- DIY and crafts: matching tools and materials specified in different units.
Feet and inches
Remember 1 foot = 12 inches, so a height like 5 ft 11 in is 71 inches = 71 × 2.54 = 180.3 cm. Convert the whole thing to inches first, then to centimetres.
Worked example
A 10-inch tablet screen measures 10 × 2.54 = 25.4 cm diagonally. Going the other way, someone 180 cm tall is 180 ÷ 2.54 = 70.87 inches, which is 5 feet 10.9 inches (since 5 ft = 60 in, the remaining 10.87 inches). Because the relationship is exact — one inch is defined as 2.54 cm — these conversions carry no rounding beyond the decimals you keep.
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 centimetres is one inch?+
Exactly 2.54 cm — this is a definition, not an approximation. To convert inches to centimetres multiply by 2.54; to convert centimetres to inches divide by 2.54.
How do I convert cm to inches?+
Divide the centimetre value by 2.54. For example 180 cm ÷ 2.54 = 70.87 inches. Just select the "Centimetres → Inches" direction in the tool.
How do I convert a height in feet and inches to cm?+
Convert the whole height to inches first (1 foot = 12 inches), then multiply by 2.54. 5 ft 11 in = 71 inches = 180.3 cm.
What size is a 55-inch TV in cm?+
The 55 inches is the diagonal: 55 × 2.54 = 139.7 cm. Screen sizes are always quoted as the diagonal, not the width.
Is the inch-to-cm conversion exact?+
Yes — since 1959 the inch has been defined as exactly 2.54 cm, so there is no rounding in the relationship itself, only in the decimal places you choose to keep.
How many inches is 1 metre?+
1 metre = 100 cm = 100 ÷ 2.54 = 39.37 inches. That is just over 3 feet 3 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: