Height Converter Calculator
Human height between feet/inches mixed format and centimetres
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What this calculator computes
Height conversion between US-customary feet-and-inches and metric centimetres is the most common cross-system measurement task in everyday life because almost every adult cares about their height in some context — medical intake, fitness apps, dating profiles, clothing size charts, anthropometric data sets. The calculator handles the mixed-unit feet-and-inches format that Americans use conversationally ("5 feet 10 inches" or "5'10") and converts cleanly to the metric figure that medical clinics, international fitness apps, and global ergonomic data sets expect. The reverse direction also matters: a metric height like 178 cm needs to land in the mixed feet-and-inches format that US audiences read on driver's licences, growth charts, and personal-fitness records. The conversion factor is exact (1 inch = 2.54 cm by 1959 international agreement), but the format conversion is what most users get wrong: the decimal-feet form ("5.10 feet") is not equivalent to the mixed feet-and-inches form ("5 feet 10 inches"), and confusing the two introduces nearly 9 inches of height error. The calculator handles all four directions: feet-and-inches to centimetres, centimetres to feet-and-inches, decimal feet to centimetres, and centimetres to decimal feet — with each direction useful for a specific downstream context. Medical clinics, fitness apps, US driver's licence offices, dating platforms, and ergonomic-data sets all encounter cross-format height conversions routinely, with the format-conversion errors being the most common source of cross-system height-data mistakes.
Calculator
The formula
Formula
cm = (feet × 12 + inches) × 2.54
Worked example
When to use this calculator
Use this calculator for medical-intake form completion at international clinics, fitness-app onboarding where the height field accepts either unit, dating-profile creation that lets users specify in either format, US driver's licence applications that record imperial height, and any cross-border situation where height needs to land in a different unit system than the user's mental default. The calculator is also useful for translating between historical and modern records: US census records before 1980 use feet and inches, while modern US health data sometimes records both unit forms for cross-referencing. The calculator does not substitute for properly trained medical anthropometric measurement (where standing height, recumbent length, and crown-rump length each have specific protocols) and does not handle pediatric growth-percentile lookups, which require age-and-sex-adjusted charts rather than simple unit conversion.
Common input mistakes
- Treating "5.10 feet" decimal form as equivalent to "5 feet 10 inches" mixed form. The decimal 5.10 feet equals 5 feet 1.2 inches (decimal 0.10 of a foot is 1.2 inches, not 10 inches), so converting 5.10 ft to cm gives 155.5 cm — about 22 cm short of the correct 177.8 cm for a 5'10" person. The two formats look similar but represent different numbers, and the confusion is one of the most common errors in cross-system height data.
- Forgetting the multiplication-by-12 step when converting mixed feet-and-inches input. A 5 ft 10 in height needs to first convert to total inches (5 × 12 + 10 = 70) before multiplying by 2.54. Skipping the foot-to-inch step and converting only the 10-inch remainder gives 25.4 cm rather than the correct 177.8 cm — a 152 cm error, off by an order of magnitude.
Frequently asked questions
How tall is 5 feet 10 inches in centimetres?
Five feet ten inches converts to (5 × 12 + 10) inches × 2.54 = 70 inches × 2.54 = 177.80 cm. That is just above the median US adult male height (about 175.5 cm) and is what a metric medical chart would record on intake. Most clinical contexts round to one decimal place, recording the figure as 177.8 cm.
How do I convert centimetres to feet and inches?
Divide the cm figure by 2.54 to get total inches, then divide the inches by 12 to get whole feet with the remainder as inches. A 178 cm height becomes 178 ÷ 2.54 = 70.08 inches, then 70.08 ÷ 12 = 5 feet with 10.08 inches remainder, giving 5 feet 10 inches (rounded). Most US contexts round the inch remainder to the nearest whole inch or half inch.
What is the difference between 5.10 ft and 5 ft 10 in?
The decimal form 5.10 ft means 5 feet plus 0.10 of a foot, where 0.10 ft equals 1.2 inches — so 5.10 ft is 5 feet 1.2 inches, equivalent to 155.5 cm. The mixed form 5 ft 10 in means 5 feet plus 10 inches, equivalent to 70 inches and 177.8 cm. The two formats produce 22 cm of difference, large enough to misclassify a person from "above median height" to "well below median". Always specify which format the figure uses.
How do I enter my height in a metric medical chart?
Convert your feet-and-inches height to centimetres using the formula (feet × 12 + inches) × 2.54, then round to one decimal place. A 5 feet 10 inches height becomes 177.8 cm; a 6 feet exactly height becomes 182.9 cm; a 5 feet 4 inches height becomes 162.6 cm. Some charts accept both unit systems and convert automatically; others expect the cm figure directly.
What is the average adult height?
Average heights vary by sex and country but cluster around 175 cm (5 ft 9 in) for adult males and 162 cm (5 ft 4 in) for adult females in most of Europe and the Americas. Northern European populations average slightly taller (Dutch men average about 184 cm, 6 ft 0 in); East Asian populations average slightly shorter (Japanese women average about 158 cm, 5 ft 2 in). The numbers shift with each generational cohort due to nutrition, healthcare, and genetic factors.