Mass vs Weight

Calculate the relationship between mass and weight using Newton's Second Law. Convert between SI units (kg, N), British Gravitational units (slugs, lbf), and English Engineering units (lbm, lbf).

Calculator

Inputs

Mass (kg)

Acceleration of Gravity

Results

Weight (SI Units)-- N

Weight (SI - Kilonewtons)-- kN

System	Mass Unit	Force/Weight Unit	Gravity Constant	Base Formula
SI (International System)	kg	N (Newton)	9.807 m/s²	Fg = m × ag
BG (British Gravitational)	slug	lbf (pound-force)	32.174 ft/s²	Fg = m × ag
EE (English Engineering)	lbm (pound-mass)	lbf (pound-force)	32.174 ft/s²	Fg = (m × ag) / gc

Mass (kg)	Weight (N)	Weight (kN)	Weight (lbf)	Notes
1	9.807	0.0098	2.205	1 kg standard weight on Earth
1644	16122.7	16.1	3627.8	Example: car mass
100	980.7	0.981	220.5	Common example mass
1	1.62	0.0016	0.364	Same 1 kg mass on Moon