Inches to Centimetres Converter
Convert between inches, centimetres, millimetres, metres, feet and yards; enter a height in feet and inches or get the result that way. An inch is exactly 2.54 cm.
- Conversion factor1 in = 2.54 cm
- Centimetres2.54 cm
- Inches1 in
- Feet and inches0 ft 1 in (0′ 1″)
In every unit
How it is calculated
The inch is a unit of length used in the US and the UK. Since 1 July 1959 the national standards laboratories of the US and the other English-speaking countries have used the international yard: exactly 0.9144 m, which makes the inch exactly 25.4 mm (US Federal Register, 24 FR 5348). UK law also defines the yard as 0.9144 m, the foot as 1/3 yard and the inch as 1/36 yard (Weights and Measures Act 1985, Schedule 1). So 1 in = 2.54 cm, 1 ft = 12 in = 30.48 cm and 1 yd = 3 ft = 91.44 cm, exactly, not approximately. In Turkey inches are common in screen, wheel-rim and pipe sizes, and feet in flight altitudes.
cm = in × 2.54 · in = cm ÷ 2.54 · 1 ft = 12 in = 30.48 cm- Inches to centimetres: inches × 2.54 (55 in × 2.54 = 139.7 cm).
- Centimetres to inches: cm ÷ 2.54 (100 cm ÷ 2.54 ≈ 39.37 in).
- Feet + inches: feet × 30.48 + inches × 2.54; 1 foot = 12 inches = 30.48 cm.
- To get feet and inches, divide the total inches by 12: the quotient is feet, the rest inches.
Example
A 55-inch TV has a 55 × 2.54 = 139.7 cm diagonal. A height of 6 ft 2 in is 6 × 30.48 + 2 × 2.54 = 187.96 cm. And 180 cm is 180 ÷ 2.54 ≈ 70.87 in, or 5 ft 10.87 in.
Frequently asked questions
How many centimetres is an inch?
Exactly 2.54 cm, or 25.4 mm. The value was fixed internationally in 1959; the British and American inch are the same.
How many inches is a centimetre?
1 ÷ 2.54 ≈ 0.3937 in. 10 cm is about 3.94 in, and a metre about 39.37 in.
What does a screen’s inch size measure?
The diagonal, from one corner to the opposite one. A 65-inch TV has a 65 × 2.54 = 165.1 cm diagonal; its width and height are shorter, depending on the aspect ratio.
How tall is 5 feet 11 inches in cm?
5 × 30.48 + 11 × 2.54 = 180.34 cm. Choose “Feet + inches (height)” as the unit you enter to type feet and inches separately.
How many metres is a foot?
Exactly 0.3048 m (30.48 cm). In aviation, 10,000 feet is exactly 3,048 metres.
Source
- US Federal Register 24 FR 5348 (1 July 1959): Refinement of values for the yard and the pound (1 yd = 0.9144 m; 1 in = 25.4 mm)
- UK Weights and Measures Act 1985, Schedule 1 Part VI (yard, foot, inch)
- NIST: The US survey foot and the international foot (1959)
- NIST SP 811, Appendix B.9: Conversion factors