Inches to cm converter
Convert inches to cm in one step – an inch is exactly 2.54 centimetres. Besides both directions, the converter shows tape-measure fractions such as 3 15/16″, turns height in feet and inches into cm, and works out a TV or monitor’s diagonal, width and height from its size in inches.
Example: What do you want to convert: Length (inches ↔ cm) · Direction: inches to cm · Value 10 → Result: 10 in = 25.4 cm. Source: Weights and Measures Act 1985, Schedule 1 Part VI – yard = 0.9144 m, inch = 1/36 yard (= 2.54 cm). Updated: .
How it is calculated
Inches to cm formula
cm = inches × 2.54 and inches = cm ÷ 2.54. This is exact: since 1959 the international inch has been defined as 2.54 cm, and a foot is 12 inches = 30.48 cm.
- 1″ = 2.54 cm · 10″ = 25.4 cm · 12″ = 30.48 cm
- 10 cm = 3.94″ ≈ 3 15/16″
- 5 ft 11 in (5′11″) = 180.34 cm
Height in feet and inches
Choose "Height" and enter feet and inches: 5′6″ is 167.6 cm, 5′10″ is 177.8 cm and 6′0″ is 182.9 cm. Going the other way, enter cm under "cm to inches" – from 12 inches upwards the result is also shown in feet and inches.
TV, monitor and laptop sizes
Screens are measured diagonally in inches. A 55-inch TV has a 139.7 cm diagonal; at 16:9 the picture is 121.8 cm wide and 68.5 cm high. Width and height follow from Pythagoras: width = diagonal × 16 ÷ √(16² + 9²). Pick your device’s aspect ratio – many laptops use 16:10 or 3:2.
| Size | Diagonal | Width × height (16:9) |
|---|---|---|
| 32″ | 81.3 cm | 70.8 × 39.9 cm |
| 43″ | 109.2 cm | 95.2 × 53.5 cm |
| 55″ | 139.7 cm | 121.8 × 68.5 cm |
| 65″ | 165.1 cm | 143.9 × 80.9 cm |
Tape-measure fractions
US tape measures are marked in sixteenths of an inch, so the converter also rounds cm to the nearest 1/16″. Careful with pipes and threads: sizes like "½ inch" are nominal sizes, not the actual diameter.
Measure on screen with the online ruler. More converters: kg to lbs and Fahrenheit to Celsius; check your display’s pixels with what is my screen resolution.
Frequently asked questions
How many cm is an inch?
Exactly 2.54 cm – the international definition since 1959.
How do I convert inches to cm?
Multiply by 2.54. Example: 15 in × 2.54 = 38.1 cm. To go from cm to inches, divide by 2.54.
How tall is 5 foot 10 in cm?
5′10″ is 70 inches × 2.54 = 177.8 cm.
How big is a 55-inch TV in cm?
Its diagonal is 139.7 cm. At 16:9 the picture is about 121.8 cm wide and 68.5 cm high; with the bezel the set is slightly larger.
How many inches is 10 cm?
10 cm is 3.94 inches, or about 3 15/16″ on a tape measure.
Sources and legal basis
- Weights and Measures Act 1985, Schedule 1 Part VI – yard = 0.9144 m, inch = 1/36 yard (= 2.54 cm)
- NIST SP 811, Appendix B.8 – inch = 2.54 × 10⁻² m (exact)
As of:
Related tools
- Online ruler in actual sizeOnline ruler for your phone or screen: calibrate once with a bank card, then measure in cm, mm or inches at real size. Free, no app and no sign-up.
- kg to lbs converterConvert kg to lbs and back: 1 kg = 2.2046 lb. Shows pounds and ounces, stone and pounds, grams, tons and a kg to lbs chart – exact to the legal definition.
- Fahrenheit to Celsius converterConvert Fahrenheit to Celsius and back: °C = (°F − 32) ÷ 1.8. Also Kelvin, Rankine and Réaumur, with the working shown and a chart of common temperatures.
- Aspect Ratio CalculatorCalculate the aspect ratio from width and height (1920 × 1080 = 16:9), find the missing side, decimal value, nearest standard ratio and CSS aspect-ratio.
- What is my screen resolution?Instantly see your screen resolution, physical pixels, browser viewport, devicePixelRatio, aspect ratio and CSS breakpoint. Live, right in your browser.
- Bar to psi converterConvert bar to psi and back: 1 bar = 14.504 psi. Also pascal, kPa, atm, mmHg and water column – with the working, a chart and a note on psig vs psia.