F = m·a m = F / a · a = F / m · weight W = m·g

Newton's Second Law: Force, mass and acceleration — the heart of dynamics. This free calculator solves for Force, mass, acceleration, weight and shows every step.

The physics

The net force on an object equals its mass times its acceleration, in the same direction. It is the quantitative heart of mechanics and is fully vector — components add independently. Weight is simply F = ma with a = g.

Worked example

m = 10 kg, a = 3 m/s². F = 10·3 = 30 N. That same 10 kg weighs 10·9.81 = 98.1 N on Earth.

Common uses

Structural and mechanical engineering, rocketry, automotive design, and essentially every dynamics problem in mechanics.

Frequently asked questions

What is the formula for Newton's Second Law?

Newton's Second Law uses the formula F = m·a. Force, mass and acceleration — the heart of dynamics.

How do you calculate Newton's Second Law?

Choose which variable to solve for, enter the values you know (in any supported unit), and the calculator substitutes them into F = m·a and shows every step of the working. It can solve for Force, mass, acceleration, weight.

Is the Newton's Second Law calculator free to use?

Yes — every Physics Fundamentals calculator is completely free, with no login, no ads and no usage limits.