Force Calculator
Calculate force from mass and acceleration (F = ma).
Try an example
98
About this calculator
How This Force Calculator Works
Enter a mass and an acceleration, and the calculator returns the force required to produce that acceleration.
The Formula
F = ma — Newton's second law. Force equals mass times acceleration, measured in newtons when mass is in kilograms and acceleration is in meters per second squared.
Worked Example
The default values — 10 kg at 9.8 m/s² — show the force of gravity on a 10 kg object near Earth's surface: 98 newtons, which is that object's weight. (9.8 m/s² is standard gravitational acceleration on Earth.)
Worked example
A 10 kg object accelerating at 9.8 m/s² (Earth's gravity) experiences 98 newtons of force — its weight, about 22 lbf.
Frequently asked questions
What is Newton's second law?
Force equals mass times acceleration (F = ma) — the more mass an object has, or the faster it accelerates, the more force is required.
Why does the default use 9.8 m/s²?
That's the standard acceleration due to gravity near Earth's surface, so this default shows the force of gravity on a 10 kg object — its weight.
What's the difference between mass and weight?
Mass is constant everywhere; weight is the force of gravity on that mass, so it changes depending on which planet (or acceleration) you use.
What units does this use?
Mass in kilograms, acceleration in m/s², force in newtons (kg·m/s²) — with a pound-force (lbf) conversion shown alongside.