Feet ↔ Meters Pull-Tape Converter

On July 1, 1959, the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa signed the International Yard and Pound Agreement, fixing the international yard at exactly 0.9144 meter and the international pound at exactly 0.45359237 kilogram. The international foot, defined as 1/3 of the yard, became exactly 0.3048 meter. Before 1959, each country had slightly different foot definitions traceable to national prototype bars; the agreement ended a century of micrometer-scale discrepancies in cross-border construction and surveying.

The foot itself is a remarkably ancient unit, dating to the Roman pes of about 296 mm (slightly shorter than the modern foot). Medieval English statutes — most famously the 1305 Composition of Yards and Perches under Edward I — defined a foot as 12 inches and a yard as 3 feet. The Tudor period stabilized the foot at the value (304.8 mm) we use today. The choice of 12 inches per foot rather than 10 reflects the Roman uncia (twelfth) — useful because 12 has more divisors than 10, making fractional carpentry tractable without calculators.

The METRE was originally defined in 1791 by the French Academy of Sciences as 1/10,000,000 of the meridian distance from the equator to the north pole through Paris. By 1799 a platinum-iridium Mètre des Archives was deposited in the French archives. In 1889 the metre became defined by a more precise platinum-iridium bar at the BIPM (Bureau International des Poids et Mesures) in Sèvres, France. In 1960 the metre was redefined as 1,650,763.73 wavelengths of krypton-86's red-orange spectral line. In 1983 the metre received its modern definition: the distance light travels in 1/299,792,458 of a second, fixing the speed of light at exactly c = 299,792,458 m/s.

The US Survey foot is a footnote in this story. Defined as 1200/3937 m ≈ 0.3048006 m, it is about 2 parts per million LONGER than the international foot. The difference accumulates to ~3.2 mm per mile or ~0.32 m per 1000 mile (610 km) survey baseline — significant for state-plane coordinate systems and federal land surveys. NOAA, NGS, and USGS officially deprecated the US Survey foot on December 31, 2022. All new federal land surveys must use the international foot or meter directly; legacy data is converted with the 2 ppm offset noted on plats.

In everyday usage, the US, UK, and a handful of small nations (Myanmar, Liberia) still use feet for height, building heights, room dimensions, and aviation altitudes. The rest of the world uses meters universally. ICAO mandates feet for aviation altitudes globally except in Russia and China. SCUBA diving uses feet in the US and metric meters elsewhere. Soccer fields, Olympic events, and scientific publishing use meters universally. The conversion factor 0.3048 meter per foot is so common in modern engineering software (CAD, BIM, simulation) that almost no engineer memorizes it any more — they just type the unit and let the software handle the math.

For most practical purposes, a useful approximation is 1 ft ≈ 0.3 m (~1.6% short) or the slightly better 3 ft ≈ 1 m (~9% long; the exact factor is 3.28 ft/m). For quick mental math, 6 ft ≈ 1.83 m, 10 ft ≈ 3 m (1.6% short), 100 ft ≈ 30 m. For engineering work always use the exact 0.3048 factor — modern calculators and spreadsheets handle the math without approximation error.

Every value in this tool routes through the exact 1959 international foot factor (0.3048 m per ft, stored to full IEEE 754 double-precision). Construction professionals working across imperial and metric drawings can rely on bit-perfect round-tripping; a value typed in feet, converted to meters, and converted back to feet returns the exact original.