Acceleration from Force Calculator
Calculate acceleration, force, or mass using Newton's Second Law (F = ma).
Solve for any of the three variables.
Newton’s Second Law of Motion is one of the most fundamental equations in all of physics:
F = m × a
Where:
- F = Force, measured in Newtons (N) — 1 Newton = 1 kg·m/s²
- m = Mass, measured in kilograms (kg)
- a = Acceleration, measured in meters per second squared (m/s²)
This law states that the net force on an object equals its mass multiplied by its acceleration. Equivalently:
- a = F / m — acceleration equals force divided by mass
- m = F / a — mass equals force divided by acceleration
Understanding each variable:
Force (F): A push or pull on an object. Forces include gravity (weight), friction, tension, thrust, and normal force. The unit is the Newton — approximately the force needed to accelerate 1 kg by 1 m/s² (or roughly the weight of an apple).
Mass (m): A measure of how much matter an object contains. Mass is NOT the same as weight. Mass is the same everywhere; weight depends on local gravity. On the Moon (g ≈ 1.62 m/s²), your mass is unchanged but your weight is 1/6 of Earth’s.
Acceleration (a): The rate of change of velocity. Positive acceleration means speeding up; negative acceleration (deceleration) means slowing down. Earth’s gravitational acceleration is 9.81 m/s².
Practical examples:
- A 1,000 kg car accelerating at 3 m/s² requires: F = 1000 × 3 = 3,000 N of net force
- A 70 kg person falling freely accelerates at 9.81 m/s² due to: F = 70 × 9.81 = 686.7 N (their weight)
- A rocket producing 1,000 N of thrust pushing a 200 kg payload: a = 1000 / 200 = 5 m/s²
Unit conversion reference:
- 1 kN (kilonewton) = 1,000 N
- 1 lbf (pound-force) = 4.448 N
- g (standard gravity) = 9.81 m/s²