Force Calculator
Free online Force Calculator. Simple, fast, and secure tool running in your browser.
Free Online Force Calculator — F = ma
Our Force Calculator is a free physics tool that instantly calculates force, mass, or acceleration using Newton's Second Law of Motion: F = m × a. Enter any two known values and the calculator solves for the third — making it ideal for physics students, engineers, and educators who need quick, accurate calculations.
The calculator supports multiple unit systems (SI and Imperial) and provides a clear breakdown of the calculation, showing the formula used and the step-by-step solution. No installation or account required — works directly in your browser on any device.
The Force Formula Explained
F = m × a
F
Force (Newtons)
m
Mass (kilograms)
a
Acceleration (m/s²)
Solve for Force
F = m × a
Solve for Mass
m = F ÷ a
Solve for Acceleration
a = F ÷ m
Worked Examples
Example 1: Pushing a Shopping Cart
A shopper pushes a 15 kg cart with an acceleration of 2 m/s².
F = 15 kg × 2 m/s² = 30 Newtons
Example 2: Car Braking Force
A 1,200 kg car decelerates at 8 m/s² to stop at a red light.
F = 1,200 kg × 8 m/s² = 9,600 Newtons
Example 3: Weight of a Person
A 70 kg person standing on Earth (g = 9.81 m/s²).
F (weight) = 70 kg × 9.81 m/s² = 686.7 Newtons