Feet to Inches converter (ft → in)

ft to in formula

Worked example: 3 ft = 36 in. The defining value behind this factor is documented on our length & distance standards page.

Feet to Inches chart

Includes standard reference values plus the specific numbers people search for most.

Most-searched ft to in answers

When to convert ft to in

• ▸Height & body measurements — a person who is 40362 ft tall is described as 40362 ft in one country and the equivalent in in elsewhere on passports and medical records.
• ▸Room and furniture sizing — IKEA and international furniture retailers list dimensions in both ft and in; converting 40362 ft helps you check if a sofa or bed fits.
• ▸Fitness & running — race distances, treadmill settings and GPS watches let you toggle ft/in; 40362 ft on a 5K route reads differently in in.
• ▸DIY, drilling & construction — hardware standards (screws, pipes, lumber) are sold in ft in some markets and in in others; a 40362 ft cut needs the in value on a metric ruler.
• ▸Travel — road signs, airline seat pitch and hiking maps switch between ft and in depending on country.

Common mistakes

• ✕Mixing US and international inches — since 1959 all inches are 25.4 mm exactly; older US "survey foot" values are slightly different.
• ✕Off-by-decimal errors: 1 cm = 10 mm, 1 m = 100 cm — a misplaced decimal turns a ft into a wildly wrong in.
• ✕Confusing feet with yards (1 yd = 3 ft) in DIY calculations.
• ✕The US survey foot is not the international foot. The US survey foot was 1200/3937 m (about 0.30480061 m) — roughly 2 parts per million longer than the international foot of 0.3048 m. NIST retired it for new work at the end of 2022, but old survey and land records still use it. Over a mile the difference is about 3 mm; over 100 km it is about 200 mm, which matters in surveying and geodesy and nowhere else.

Regional usage & source

Metric units (mm, cm, m, km) are used in most of the world. Imperial units (in, ft, yd, mi) are standard in the US and still common in the UK for road distances and human height.

Reference: Conversion factors are defined by the International System of Units (SI) as maintained by the BIPM (bipm.org) and NIST (nist.gov). 1 inch = exactly 0.0254 meters (international yard and pound agreement, 1959).

How these numbers are produced and rounded: methodology.

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