Thou (thou)
The thou, abbreviated as thou, is an engineering unit of length equal to one-thousandth of an inch or exactly 0.0254 millimetres (2.54×10⁻⁵ metres). Devised in 1844 by the British engineer Sir Joseph Whitworth to facilitate precise manufacturing, the unit revolutionized industrial machining. It was officially tied to the metric base unit of length in 1959 with the adoption of the International Yard and Pound Agreement.
Metric
- Kilometre (km)2.54×10⁻⁸
- Metre (m)2.54×10⁻⁵
- Decimetre (dm)2.54×10⁻⁴
- Centimetre (cm)2.54×10⁻³
- Millimetre (mm)0.03
- Micrometre (µm)25.4
- Nanometre (nm)25,400
- Angstrom (Å)254,000
Nautical
- Nautical mile1.37×10⁻⁸
- Fathom1.39×10⁻⁵
Astronomical
- Parsec (pc)8.23×10⁻²²
- Light year2.68×10⁻²¹
- Astronomical unit (AE)1.7×10⁻¹⁶
- Light minute1.41×10⁻¹⁵
- Light second8.47×10⁻¹⁴