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 fromToDo this
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 pintx 1.75975399
Litre (l or L)U.S. pintx 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
Pascal (Pa)Pounds per square inch (psi)x 0.000145038
Kelvin (K)Degrees Celsius or centigrade (°C)-273.15
Degrees Celsius or centigrade (°C)Degrees Fahrenheit (°F)x 1.8 + 32
Joule (J)foot-pound/ 1.356
Joule (J)British thermal unit (Btu)/ 1055
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


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