MeasureSparkReference dataset · Version 2026-09-13
Exact unit conversion table
Direct answer: Multiply a measurement by the listed factor to convert it to the corresponding SI base unit. For example, 10 feet × 0.3048 = 3.048 metres. These factors are definitions; rounding should happen only after the calculation.
| Category | Source unit | SI base unit | Factor | Exact definition |
|---|---|---|---|---|
| Length | inch (in) | metre (m) | 0.0254 | 1 in = 0.0254 m exactly |
| Length | foot (ft) | metre (m) | 0.3048 | 1 ft = 0.3048 m exactly |
| Length | yard (yd) | metre (m) | 0.9144 | 1 yd = 0.9144 m exactly |
| Length | mile (mi) | metre (m) | 1609.344 | 1 mi = 1609.344 m exactly |
| Length | centimetre (cm) | metre (m) | 0.01 | 1 cm = 0.01 m exactly |
| Area | square foot (ft²) | square metre (m²) | 0.09290304 | 1 ft² = 0.09290304 m² exactly |
| Area | square yard (yd²) | square metre (m²) | 0.83612736 | 1 yd² = 0.83612736 m² exactly |
| Area | acre (acre) | square metre (m²) | 4046.8564224 | 1 acre = 4046.8564224 m² exactly |
| Area | hectare (ha) | square metre (m²) | 10000 | 1 ha = 10000 m² exactly |
| Volume | cubic foot (ft³) | cubic metre (m³) | 0.028316846592 | 1 ft³ = 0.028316846592 m³ exactly |
| Volume | cubic yard (yd³) | cubic metre (m³) | 0.764554857984 | 1 yd³ = 0.764554857984 m³ exactly |
| Volume | US liquid gallon (US gal) | cubic metre (m³) | 0.003785411784 | 1 US gal = 0.003785411784 m³ exactly |
How should these factors be used?
Multiply a value in the source unit by factor to obtain the listed SI base unit. Area factors are derived by squaring the underlying length conversion and volume factors by cubing it.
Important unit distinctions
A US liquid gallon is different from an imperial gallon. Confirm the unit system before converting a product label, plan or specification. Keep the full published factor during calculation and round the final result to the precision your project supports.