Newton\u2019s Second Law Calculator (F = ma)

This Newton\u2019s second law calculator works with the most famous equation in mechanics, force equals mass times acceleration. Choose whether you want the force, the mass or the acceleration and enter the other two; the calculator rearranges F = ma and solves for it. Newton\u2019s second law says the net force on an object equals its mass times the acceleration that force produces, which is why a heavier object needs more force for the same acceleration. Use SI units: newtons, kilograms and metres per second squared. The formula, a worked example and the assumptions are below.

Force (N)

Mass (kg)

Acceleration (m/s\u00B2)

Solve for

Value

Result

The formula

Newton\u2019s second law is F = ma, where F is the net force, m is mass and a is acceleration. Rearranged: m = F / a and a = F / m.

Worked example

A net force on a 10 kg mass producing 2 m/s squared of acceleration is F = 10 times 2 = 20 N. Solve for F with m = 10, a = 2 to confirm.

Frequently asked questions

What is Newton\u2019s second law?

The net force on an object equals its mass times its acceleration: F = ma.

Does F mean total force?

Yes, the net (resultant) force. Add up all forces, including friction and gravity, before using the law.

What is a newton?

The SI unit of force: one newton accelerates one kilogram at one metre per second squared.

Who this calculator is for

This calculator is for physics students, teachers and engineers.

What this calculator assumes

You enter SI units as labelled.
One variable is solved from the others.
Results are rounded for display.

Formula and sources

Related calculators

Kinetic Energy Calculator: energy of motion.
Momentum Calculator: mass times velocity.
Projectile Motion Calculator: range and height.

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