Appendix C Units and Conversion Factors
meter (m) |
= 39.37 inches (in.) |
centimeter (cm) |
= 0.01 m (exact, definition) |
millimeter (mm) |
= 0.001 m (exact, definition) |
kilometer (km) |
= 1000 m (exact, definition) |
angstrom (Å) |
= 10–8 cm (exact, definition) |
yard (yd) |
= 0.9144 m |
inch (in.) |
= 2.54 cm (exact, definition) |
mile (US) |
= 1.60934 km |
liter (L) |
= 0.001 m3 (exact, definition) |
milliliter (mL) |
= 0.001 L (exact, definition) |
microliter (μL) |
= 10–6 L (exact, definition) |
liquid quart (US) |
= 32 (US) liquid ounces (exact, definition) |
dry quart |
= 1.1012 L |
cubic foot (US) |
= 28.316 L |
gram (g) |
= 0.001 kg (exact, definition) |
milligram (mg) |
= 0.001 g (exact, definition) |
kilogram (kg) |
= 1000 g (exact, definition) |
ton (metric) |
= 1000 kg (exact, definition) |
ounce (oz) |
= 28.35 g |
pound (lb) |
= 0.4535924 kg |
ton (short) |
= 2000 lb (exact, definition) |
ton (long) |
= 2240 lb (exact, definition) |
4.184 joule (J) |
= 1 thermochemical calorie (cal) |
1 thermochemical calorie (cal) |
= 4.184 × 107 erg |
erg |
= 10–7 J (exact, definition) |
electron-volt (eV) |
= 1.60218 × 10−19 J |
liter∙atmosphere |
= 24.217 cal |
nutritional calorie (Cal) |
= 1000 cal (exact, definition) |
British thermal unit (BTU) |
= 1054.804 J [1] |
torr |
= 1 mm Hg (exact, definition) |
pascal (Pa) |
= N/m2 (exact, definition) |
atmosphere (atm) |
= 760 mm Hg (exact, definition) |
bar |
= 105 Pa (exact, definition) |
- BTU is the amount of energy needed to heat one pound of water by one degree Fahrenheit. Therefore, the exact relationship of BTU to joules and other energy units depends on the temperature at which BTU is measured. 59°F (15°C) is the most widely used reference temperature for BTU definition in the United States. At this temperature, the conversion factor is the one provided in this table. ↵