The International System of Units
Length
Basic unit is the meter (m), which equals 39.37 in.
| Common Multiples and Subdivisions | |
|---|
| kilometer (km) | 103 m |
| decimeter (dm) | 10-1 m |
| centimeter (cm) | 10-2 m |
| millimeter (mm) | 10-3 m |
| micrometer (µm)* | 10-6 m |
| nanometer (nm) | 10-9 m |
| angstrom (Å) | 10-10 m |
*Also called the micron (µ)
Mass
Basic unit is the gram (g).
| Common Multiples and Subdivisions | |
|---|
| kilogram (kg) | 103 g (2.2 lb) |
| centigram (cg) | 10-2 g |
| milligram (mg) | 10-3 g |
| microgram (µg) | 10-6 g |
Volume
Basic unit is the liter, which equals 1 cubic decimeter, dm3 (1.06 quart). A liter of water at its maximum density weighs almost 1 kg. Therefore, 1 ml (= 10-3 liter) of water weighs, for all practical purposes, 1 g. One cubic centimeter (cm3 or cc) is 10-3 dm3. Therefore, it is equal to 1 ml, and the units ml and cc are used interchangeably.
Temperature
Basic unit is the Celsius (formerly known as centigrade) degree, oC. 0oC is the freezing point of water; 100oC is the boiling point of water. To convert from oC to oF (Fahrenheit) or vice versa: oF - 32 = 9/5 oC.
Useful Equivalents
1 inch = 2.54 cm
1 oz = 28.35 g
1 lb = 453.6 g
1 U.S. fluid oz = 29.57 ml
1 U.S. liquid qt = 0.946 liter (l)
8 December 1996