Force Calculator (F = ma)
Calculate force using Newton's second law F = ma. Enter mass (kg) and acceleration (m/s²) to get force in Newtons, plus the object's weight on Earth.
How to use this tool
- Enter mass and acceleration in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your force and the full breakdown beneath it.
Newton's second law: F = ma. Force (N) equals mass (kg) times acceleration (m/s²). Weight is the force of gravity: W = mg where g = 9.81 m/s² on Earth's surface.
Frequently asked questions
- What is the difference between mass and weight?
- Mass (kg) is a measure of the amount of matter — it doesn't change with location. Weight (N) is the gravitational force on that mass, which varies by planet.
- Can acceleration be negative?
- Yes — a negative value means deceleration (the force opposes motion).