InputsLive
Convert direction
How the result is calculated
All conversions use the exact international inch definition:1 inch = 2.54 cm (exact)
  • ft/in → cm:total inches = feet × 12 + inches; cm = total inches × 2.54
  • cm → ft/in:total inches = cm ÷ 2.54; feet = floor(total ÷ 12); inches = remainder
  • Metres: cm ÷ 100.
Common height references
Heightft / incm
Average US woman54162.6
Average US man59175.3
NBA average66198.1
Jockey height limit410147.3
Result
Height in centimetres
177.8 cm
5' 10.0" = 177.8 cm = 1.778 m
Feet & inches5' 10.0"
Centimetres177.8 cm
Metres1.778 m
Total inches70 in

Uses the exact conversion: 1 inch = 2.54 cm (NIST SP 811). Results are rounded for display only.

Results are estimates. Consult a professional.

How it's calculated

How the height converter works

Height is measured in two systems that don't share a round-number bridge: the imperial system uses feet and inches, and the metric system uses centimetres and metres. The converter handles the split-unit imperial format — feet plus leftover inches — and turns it into centimetres in a single calculation. Going the other direction, it divides centimetres by the same exact factor and breaks the result back into feet and remaining inches.

cm = (feet × 12 + inches) × 2.54
total inches = cm ÷ 2.54
feet = floor(total inches ÷ 12)
inches = total inches mod 12
The exact value 1 inch = 2.54 centimetres was established by international agreement in 1959 and is codified in NIST Special Publication 811 (2008 edition), the US reference for units of measurement.
Example

Worked example: converting 5 ft 11 in to centimetres

Example: a person who is 5 feet 11 inches tall

James is filling in a health form that asks for height in centimetres. He knows he is 5 ft 11 in but the form has a single metric field. He also wants to express the result in metres for his passport application.

First, convert the feet and inches to a single inch total: (5 × 12) + 11 = 71 inches. Then multiply by the exact factor: 71 × 2.54 = 180.34 cm. Dividing by 100 gives 1.8034 m, which rounds to 1.80 m for most official documents.

180.34 cm · 1.80 m
5 ft 11 in converts to exactly 180.34 cm. James enters 180 cm on the health form (standard rounding) and 1.80 m on the passport application.
Quick reference

Height conversion chart: feet & inches to centimetres

The table below covers the heights most commonly looked up — from average child heights through typical adult ranges. All figures use the exact 2.54 cm/in factor and are rounded to one decimal place.

Feet & inchesTotal inchesCentimetresMetres
4 ft 0 in48121.91.22
4 ft 6 in54137.21.37
5 ft 0 in60152.41.52
5 ft 3 in63160.01.60
5 ft 6 in66167.61.68
5 ft 9 in69175.31.75
6 ft 0 in72182.91.83
6 ft 3 in75190.51.91
6 ft 6 in78198.11.98

Calculated using the exact NIST conversion: 1 inch = 2.54 cm exactly. Centimetre values are rounded to one decimal place; metre values to two.

Practical use

When to use a height converter and how to measure accurately

Height conversions come up in a handful of everyday situations — passport and visa forms, online clothing sizing from international brands, medical records when switching between a US provider and one overseas, and fitness apps that default to metric. In each case the stakes differ: a clothing size can be a centimetre off without consequence, while a body-mass index calculation or medical dosing formula should use the exact converted figure.

  • Passports and ID — US passports record height in feet and inches; most other countries use centimetres. Enter your exact imperial height and use the cm result with no rounding for the most accurate record.
  • Medical and health forms — BMI, drug-dosing formulas, and some anaesthesia calculations all use metric height. Use the unconverted decimal centimetre value, not a rounded whole number.
  • International clothing — EU, UK, and Asian size charts often list height ranges in centimetres. Round to the nearest whole centimetre for size comparisons.
  • Sports registrations — track and field, swimming, and gymnastics use metric; US team sports typically use feet and inches. Run the converter in whichever direction the registration form requires.
  • Home and furniture — ceiling clearance for bunk beds, overhead storage, and door frames is often specified in inches in the US but centimetres in European flat-pack instructions. Convert the measurement, not just your height.
Measure without shoes
Standard height measurement is taken barefoot, standing upright against a flat wall with heels together. Shoes add 1–4 cm depending on the sole. Medical and official records always use bare-foot height.
Accuracy & limits

Accuracy and limitations of height conversion

The conversion itself is perfectly exact: 1 inch equals 2.54 cm by definition, so the math introduces zero rounding error. Any imprecision in the final result comes entirely from the measurement you put in, not from the formula.

Two practical limits apply. First, human height varies slightly through the day — most people are about 1 cm (roughly half an inch) taller in the morning than at night because intervertebral discs compress during waking hours. Second, the converter handles only static, vertical height. It does not account for body proportions, posture, or medical limb-length measurements. For clinical purposes — growth charts, orthopaedic assessments, or body-composition analysis — use a calibrated stadiometer and record the figure to the nearest millimetre. For everyday conversions, the calculator is as accurate as the measuring tape you used. Results can also be cross-checked against the BMI calculator, which accepts height in either unit system.

Definitions

Height measurement terms defined

An imperial unit of length equal to exactly 2.54 centimetres by international agreement. There are 12 inches in one foot and 36 in one yard.
An imperial unit of length equal to 12 inches, or exactly 30.48 centimetres. Human height in the US is conventionally expressed as feet plus remaining inches (e.g. 5 ft 9 in).
One hundredth of a metre. The standard unit for recording human height in metric-system countries. Most adults are between 150 cm and 200 cm tall.
The SI base unit of length. One metre equals 100 centimetres. Height in metres is used on European passports, in sports records, and in most medical literature outside the US.
The value 1 inch = 2.54 cm is exact — it has no uncertainty — because it was fixed by international agreement in 1959 (the International Yard and Pound Agreement). NIST SP 811 codifies it as the authoritative US reference.
A calibrated instrument for measuring standing height, consisting of a vertical ruler and a horizontal headboard. Clinical measurements use a stadiometer to the nearest millimetre; home measurements with a wall and tape measure typically round to the nearest quarter inch or half centimetre.
About

About this height converter

This converter runs entirely in your browser. No height data is sent to any server, stored, or shared. The calculation uses the exact NIST-defined factor (1 in = 2.54 cm), so results match any authoritative conversion table to as many decimal places as you need.

Find more measurement tools in our home & garden calculators collection, or browse the full library of free calculators covering health, finance, and everyday maths.

Questions

Frequently asked questions about the free height converter

A height calculator is a free online tool that helps you convert height between feet & inches and centimeters / meters. Imperial and metric height conversions: 1 in = 2.54 cm exactly (NIST SP 811). It runs entirely in your browser with instant results and no sign-up.
Medical forms, ID/passport applications, gym equipment settings, international travel, dating apps. Different contexts assume different units.
The international yard was defined in 1959 as exactly 0.9144 m. That makes 1 in = 2.54 cm by definition, not approximation.
Self-reported heights run ~1 in tall vs measured (biased optimism). For medical use, get measured against a wall at the same time of day — height shrinks 1-2 cm by evening.

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