Enter a mass to calculate its weight (gravitational force) on Earth.
How to Use the Weight Calculator
One field, mass, converts straight to weight using Earth's standard gravity — there's no separate gravity input, since this one is Earth-only by design.
"How much do you weigh" is, strictly speaking, asking about mass, not weight — the two get used interchangeably in conversation, but physics keeps them separate. Mass is how much matter you have; weight is the force gravity exerts on that mass, and it changes depending on where you're standing.
weight (N) = mass (kg) × gg is standard Earth gravity, 9.80665 m/s², an internationally defined exact value. A 70 kg person weighs roughly 686 newtons here on Earth — but the same person, same 70 kg of mass, weighs only about 113 newtons on the Moon, where gravity runs at about a sixth of Earth's. Nothing about their mass changed; the local gravitational field did.
This Weight Calculator reports the result in newtons (the actual SI force unit) and pounds-force, rather than kilograms — kilograms measure mass, and using them for "weight" is the exact conflation this calculator is built to avoid.