A male African elephant can weigh 5 tons (14,000 lbs), but a blue whale can weigh 19 tons (238,000 lbs).
Mass and weight are related by Newton's law,
W=mg (Weight = Mass * Gravity). The value of gravity used for these conversions is 32.1740486 ft/s² or 9.80665 m/s². The units for force (weight) and mass are based on the equations below.
| Force | = | Mass | * | Acceleration |
English: | 1 lbf (Pound Force) | = | 1 slug | * | 1 ft/s² |
Metric: | 1 N (Newton) | = | 1 kg (Kilogram) | * | 1 m/s² |
Important: The slug is the base unit for mass in the English system, but the more common unit for mass is the Pound Mass (lbm). Under standard Earth gravity,
1 lbm weighs 1 lbf and therefore the term "
pound" is usually used for both mass and weight in the English system.
MASS Conversions
1 lbm = 0.45359237* kg (exact conversion)
1 kg = 2.2046226 lbm
1 slug = 32.1740486 lbm
1 kg = mass of 1 liter of water
1 amu = 1.66053886E-27 kg
1 metric ton = 1000 kg
WEIGHT Conversions
1 lbf = 4.44822 N
1 stone = 14 lbf
1 lbf = 16 oz
1 short ton (US) = 2000 lbf
1 long ton (UK) = 2240 lbf
Mix of Mass & Weight
1 oz = 28.349523 g