Unit Conversion
Generally I use SI units (i.e. metric) - their creation was one of Napoleon's better acts, and they are now wtandard internationally for scientific and most engineering work, as well as in most countries.
However there are 3 countries in the world (USA, Libya and the Cayman Islands) who have stuck to what were called Imperial units when I was growing up, i.e. feet, inches and pounds. Also, some countries still use these for some measures, e.g. in the UK traffic speeds are in miles per hour, and older people (like myself) in older countries were initially schooled in these units, and may be more familiar with them than their metric equivalents.
For these reasons, I have drawn up the table below to convert from SI to other units.
| Convert from | To | Do this |
| Length | ||
| Metre (m) | Foot (ft or ') | x 0.3048 |
| Millimetre (mm) | Inch (in or ") | / 25.4 |
| Square meter (m2) | Square foot ( (ft2 or sq.ft.) | x 0.092903 |
| Cubic meter (m3) | Cubic foot ( (ft3 or cu.ft.) | x 0.0283168 |
| Litre (l or L) | Cubic meter (m3) | x 0.001 |
| Litre (l or L) | Imperial pint | x 1.75975399 |
| Litre (l or L) | U.S. pint | x 2.11337641 |
| Mass, Weight and Force | ||
| Kilogram (kg) | Pound (lb) | x 0.453592 |
| Newton (N) | Pound-force (lbf) | x 0.22481 |
| Density (kg/m3) | Pounds per cubic foot (lb/ft3) | / 16.0185 |
| Pressure | ||
| Pascal (Pa) | Pounds per square inch (psi) | x 0.000145038 |
| Temperature | ||
| Kelvin (K) | Degrees Celsius or centigrade (°C) | -273.15 |
| Degrees Celsius or centigrade (°C) | Degrees Fahrenheit (°F) | x 1.8 + 32 |
| Energy | ||
| Joule (J) | foot-pound | / 1.356 |
| Joule (J) | British thermal unit (Btu) | / 1055 |
| Power | ||
| Watt (W) | horsepower | / 745.7 |
| Heat and Insulation | ||
| RSI (K.m2/W or °C.m2/W) | R (°F.ft2.h/Btu) | x 5.67826 |
| Specific heat capacity (J.kg-1.K-1 or J.kg-1.°C-1) | Btu.lb-1.°F-1) | / 4177.6 |
| Thermal conductivity (W.m-1.K-1 or W.m-1.°C-1) | Btu.h-1.ft-1.°F-1) | / 1.730735 |