Units of Length
26 units of length in the database, across 9 measurement systems, each with its exact or best-known SI value.
| Unit | Symbol | Quantity | Value in SI |
|---|---|---|---|
| Metre | m | Length | Base unit; c = 299,792,458 m/s exactly |
| Ångström | Å | Length | 1 Å = 10⁻¹⁰ m = 0.1 nm (exact) |
| Inch | in | Length | 25.4 mm (exact) |
| Foot | ft | Length | 0.3048 m (exact) |
| Yard | yd | Length | 0.9144 m (exact) |
| Mile | mi | Length | 1609.344 m (exact) |
| Fathom | ftm | Length | 1.8288 m (exact) |
| Chain | ch | Length | 20.1168 m (exact) |
| Rod | rd | Length | 5.0292 m (exact) |
| Furlong | fur | Length | 201.168 m (exact) |
| Hand | hh | Length | 101.6 mm (4 inches, exact) |
| US survey foot | ft (US) | Length | 1200/3937 m ≈ 0.3048006 m |
| Astronomical unit | au | Length | 149,597,870,700 m (exact) |
| Light-year | ly | Length | 9,460,730,472,580,800 m (exact) |
| Parsec | pc | Length | 648,000/π au ≈ 3.0857 × 10¹⁶ m |
| Nautical mile | NM | Length | 1852 m (exact) |
| Shaku | 尺 | Length | 10/33 m ≈ 30.30 cm |
| Chi | 尺 | Length | 1/3 m (market chi) |
| Li | 里 | Length | 500 m (market li) |
| Verst | верста | Length | 1066.8 m (500 sazhen) |
| Arshin | аршин | Length | 71.12 cm (28 inches) |
| Toise | toise | Length | ≈ 1.949 m (6 pieds du roi) |
| Ell | ell | Length | English ell: 45 in = 1.143 m |
| Royal cubit | meh niswt | Length | ≈ 523–525 mm |
| Roman foot | pes | Length | ≈ 296 mm |
| Roman mile | mille passuum | Length | ≈ 1480 m |