Weight versus mass
Mass is the amount of matter in an object and stays the same everywhere. Weight is the force gravity pulls on that mass, so it changes with location.
The tool multiplies your mass by the gravitational acceleration you supply to get the force, then reports it in newtons and pounds-force.
- Mass is measured in kilograms; weight here is a force.
- On Earth, gravity is about 9.80665 m/s².
Reading the result
Newtons are the SI unit of force and pounds-force is the customary equivalent; one pound-force is about 4.448 newtons. Use whichever your task expects.
Changing gravity
Swap in a different gravity to see how weight shifts on other bodies, even though the mass is unchanged.
- The Moon is roughly 1.62 m/s², about a sixth of Earth's.
- Mars is roughly 3.71 m/s².
Common mistakes
A bathroom scale reads in kilograms, but that is your mass, not your weight in newtons. Enter that figure as the mass and let the tool compute the force.
Use a positive gravity value; entering zero or a negative number does not describe a normal gravitational pull.
Formula
W = m·g