Convert Foot (ft) (ft) to Millimeter (mm) (mm)
Category: Length
2.5 ft = 762 mm
High-precision rounding: 6 decimals
How to convert foot (ft) to millimeter (mm)
We convert by pivoting through the SI base unit for Length and applying exact factors where applicable.
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Examples
Linear unit conversions use standardized factors; many are exact by definition (e.g., 1 in = 25.4 mm, 1 ft = 0.3048 m).
Common mistakes
- Confusing international foot (0.3048 m) with legacy ‘US survey foot’ in old datasets.
- Rounding mid-calculation; keep precision to the end.
About Length
Length measures distance or size. In SI it derives from the meter, defined via the speed of light, which ensures exact, reproducible conversions. Typical applications include construction, mapping, manufacturing tolerances, and navigation; legacy units like inches and feet remain common in trade and building plans.
About Foot (ft)
Foot (ft)
Equals 12 inches; exactly 0.3048 m. Common for human height, room dimensions, and altitude in aviation (with feet for flight levels).
History: Standardized as the ‘international foot’ in 1959; the legacy US survey foot persisted for geodesy until its retirement in 2023 in favor of the international definition.
About Millimeter (mm)
Millimeter (mm)
Equals 1/1000 of a meter. Used for tolerances, mechanical parts, PCB traces, and rainfall amounts. Ideal when sub-centimeter precision is required.
History: Adopted alongside other metric submultiples; machine tooling and metrology standardized on millimeters to simplify interchangeability.