Feet to Cm Converter

Yes, exactly, with no rounding. The 1959 International Yard and Pound Agreement, signed by the US, UK, Canada, Australia, New Zealand, and South Africa, fixed the international yard at exactly 0.9144 m. Dividing by 3 gives 1 ft = 0.3048 m = 30.48 cm, and dividing again by 12 gives 1 in = 0.0254 m = 2.54 cm. Every conversion in this calculator chains off that one defined ratio, so the factor itself carries no measurement uncertainty.

The international foot is exactly 0.3048 m (30.48 cm). The US Survey foot was defined as 1200 / 3937 m, which is roughly 0.30480061 m (about 30.4800609601 cm). The gap is about 2 parts per million, or roughly 1 cm over 5 km, which is negligible for everyday work but big enough to dislocate geodetic survey markers if you mix the two systems. NIST, NOAA, and the US National Geodetic Survey retired the US Survey foot for federal use on 1 January 2023, so the international foot is now the only standard for tape measures, building codes, aviation charts, and survey work. This converter uses the international foot.

Global averages sit close to 5 ft 9 in (175 cm) for adult men and 5 ft 4 in (162 cm) for adult women, per the NCD Risk Factor Collaboration's 200-country dataset. The tallest national averages run about 5 ft 11.7 in (182 cm) for Dutch men and 5 ft 6.5 in (169 cm) for Latvian women. The shortest averages sit near 5 ft 2.6 in (159 cm) for men in Timor-Leste and 4 ft 11 in (150 cm) for women in Guatemala. US adult averages reported by the CDC are 5 ft 9 in (175 cm) for men and 5 ft 4 in (162 cm) for women, which is why the calculator flags any value in the 4 ft to 8 ft window as human height.

The centimeter is one hundredth of a meter, and the meter is the base length unit of the metric system, adopted in revolutionary France in 1795. The original meter was defined as one ten-millionth of the distance from the Earth's equator to the North Pole along the Paris meridian, surveyed by Delambre and Mechain between 1792 and 1799. That definition was replaced in 1889 by a platinum-iridium prototype bar, in 1960 by a specific number of wavelengths of krypton-86 light, and since 1983 by the distance light travels in vacuum in 1 / 299,792,458 of a second. The factor between centimeters and meters has stayed fixed at 100 the entire time, so any historical meter converts cleanly to centimeters.

Inertia, mostly. The US, the UK (informally), and Liberia still report adult height in feet and inches because that is what tape measures, doctors' charts, drivers' licenses, and everyday conversation have always used. Every other country measures height in centimeters because the metric system is the legal standard for trade, education, and government. The split tracks the broader metrication map: the US never enforced metric conversion for daily life after the 1975 Metric Conversion Act made it voluntary, the UK partially metricated road signs (miles still) and food labels (kilograms with optional pounds), and the rest of the world standardized on centimeters and meters decades earlier. Both systems are exact and interchangeable; the calculator handles either direction with the 1 ft = 30.48 cm factor.