Mass Weight Converter
Free online weight unit converter.
Convert between all weight units instantly with accurate results, formulas, and reference tables.
No signup required.
Last updated · How we build & check our tools
Frequently Asked Questions
Common questions about the Mass Weight Converter
Mass is amount of matter (kg). Weight is gravitational force (newtons). On Earth, 1 kg mass weighs 9.8 N.
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Sources & References
International System of Units (SI): mass and weight
Mass and weight is measured in the kilogram (kg); 1 lb = 0.45359237 kg exactly. Conversions between SI and other units use exact, internationally agreed factors maintained by NIST.
International System of Units (SI)
Authoritative definitions for mass and weight, from the BIPM SI Brochure (9th edition), the defining reference for the SI.