Metre (m)
The metre (symbol m) is the base unit of length in the International System of Units (SI). Originally defined in 1791 by the French Academy of Sciences as one ten-millionth of the distance from the equator to the North Pole, its definition was rebased in 1983 by the 17th General Conference on Weights and Measures as the distance light travels in a vacuum in 1/299,792,458 of a second, establishing high scientific reproducibility.
Metric
- Kilometre (km)1×10⁻³
- Metre (m)1
- Decimetre (dm)10
- Centimetre (cm)100
- Millimetre (mm)1,000
- Micrometre (µm)1,000,000
- Nanometre (nm)1×10⁹
- Angstrom (Å)1×10¹⁰
Nautical
- Nautical mile5.4×10⁻⁴
- Fathom0.55
Astronomical
- Parsec (pc)3.24×10⁻¹⁷
- Light year1.06×10⁻¹⁶
- Astronomical unit (au)6.68×10⁻¹²
- Light minute5.56×10⁻¹¹
- Light second3.34×10⁻⁹