Height Converter

Converting height without the headache

Height is the measurement that most often has to cross the metric-imperial border. A passport, driving licence or medical form asks for centimetres or metres; a dating profile, a door frame, a basketball roster or a conversation in the United States answers in feet and inches. The awkward part is that feet and inches are not decimal: 5 ft 9 in is not 5.9 feet, and treating it as if it were is the single most common height conversion error, worth almost three centimetres of phantom height. This converter handles the mixed units properly: enter centimetres, or enter feet and inches separately, and read the height in every form at once.

Every conversion here uses the exact international definition agreed in 1959: one inch is exactly 2.54 centimetres. Not approximately, not a rounded rule of thumb, but the definition itself, which makes a foot exactly 30.48 cm and means converting there and back returns your starting number to the last decimal. The stats panel keeps the full precision, the headline rounds inches to one decimal place the way heights are spoken aloud, and the reference table below covers the everyday range from 140 to 200 cm so common heights can be read off without typing anything.

The formulas, both directions

Why heights are written 5′9″

The shorthand 5′9″, five feet nine inches, borrows its symbols from geometry and surveying, where the prime mark stood for feet as a first subdivision and the double prime for inches as the second. Spoken aloud it becomes "five nine", which is why you will also see heights written bare as 5-9 in American sports and medicine, a format that risks being misread as a decimal or a date everywhere else. However it is written, it is always a count of feet plus a remainder of inches under twelve, never a decimal number, and converting it always starts by turning it into a single total of inches, exactly as the formula above does.

Worked example

Both directions, worked in full. 175 cm: 175 ÷ 2.54 = 68.8976 total inches; five full feet use 60 of them, leaving 8.8976, so 175 cm = 5 ft 8.9 in, and 175 cm is also exactly 1.75 m. 6 ft 0 in: (6 × 12 + 0) × 2.54 = 72 × 2.54 = 182.88 cm.

How to use this calculator

1. Choose Metric if you know the height in centimetres, or Imperial if you know it in feet and inches.
2. Enter the height in the fields for your system.
3. Read the converted height in the headline panel.
4. Check the table for centimetres, metres, total inches and feet-and-inches side by side.
5. Use the reference table below to look up other common heights without typing.

Rounding, measuring and honest centimetres

Heights get rounded more than any other measurement. People measure themselves in shoes, in the morning (when everyone is a few millimetres taller after a night lying down), or not since their teens, and then round the conversion up on top, so a claimed height can gather a centimetre or two of optimism at every step. This calculator at least makes the arithmetic honest: it reports inches to two decimals in the stats so you can see exactly what a rounded-down centimetre entry does, and the headline's one-decimal rounding can move a result by at most about an eighth of an inch either way.

For a measurement worth converting, stand barefoot against a wall, heels and shoulders touching it, look straight ahead, and have someone rest a book flat on your head and mark its underside. Measure to the mark in whichever system your tape uses, then convert here. Children's heights, door and ceiling clearances, bike frame sizes and clothing all run on the same arithmetic; only the tolerance for rounding changes. And if a form asks for metres, remember it wants the decimal form, 1.75 m, not the feet-and-inches figure typed into the wrong box.

Working in centimetres and inches only? The dedicated Cm to Inches and Inches to Cm pages are pre-set to that pair, with full tables.

Frequently asked questions