Force Calculator
Newton's second law, F = m × a. Mass and acceleration in, force in newtons out.
Example — 5 kg accelerating at 3 m/s²15 N
For weight on Earth, set acceleration to 9.8.
How we got it — the example, step by step
- Newton's second law: F = m × a.
- = 5 kg × 3 m/s² = 15 N.
Check it backwards
15 N ÷ 5 kg = 3 m/s² — the acceleration we started with. (For weight on Earth, use a = 9.8 m/s².)
Questions people also ask
How do I get weight from mass?
Weight is the force of gravity on a mass: use this calculator with a = 9.8 m/s². A 70 kg person weighs 70 × 9.8 = 686 N on Earth.