Force Calculator

Calculate force, mass, or acceleration using Newton's Second Law: F = m × a. Enter any two values to find the third.

Enter values above to calculate.

Newton's Second Law Formula

F = m × a

Where:

  • F = force (Newtons, N)
  • m = mass (kilograms, kg)
  • a = acceleration (m/s²)

Rearranged Formulas

m = F / a
a = F / m

Example

Problem: A 5 kg object accelerates at 3 m/s². What is the force?
Solution: F = 5 × 3 = 15 N

Understanding Force

Force is any interaction that causes an object to change its velocity. One Newton is defined as the force needed to accelerate a 1 kg object at 1 m/s².

FAQ

What is a Newton?

A Newton (N) is the SI unit of force. It equals 1 kg·m/s². Approximately, it's the weight of a small apple (about 100 g under Earth's gravity).

How is weight related to force?

Weight is a special case of force where the acceleration is due to gravity (g ≈ 9.8 m/s²). Weight = mass × g.

Can force be negative?

Yes. Negative force indicates that the force acts in the opposite direction to the defined positive direction.

Last updated: 2026-08-08