Back to Unit Index
Unit Conversion
Part III: Force and Mass
From The International System of Units   NASA SP-7012
Note: an asterisk (*) after a number indicates it is exact

Force Units
To Convert From To Multiply By
pound (lbf avoirdupois) newtons 4.448 221 615 260 5*
kilogram force (kgf) newton 9.80 665*
pound (lbf avoirdupois) kilogram force (kgf) 0.45359237
ounce (ozf avoidupois) newton 0.370 685 134
ounce (ozf avoirdupois) gram force (kgf) 28.349523

Mass Units
To Convert From To Multiply By
slug kilogram 14.593 902 9
pound mass (lbm) kilogram2 0.453 592 37*