Physics

Force Calculator (F = ma)

Find the net force needed to accelerate a mass.

By TheCalcTools Updated Formula checked and tested

Your numbers

Your results

Force (N)
Force (N)
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Weight on Earth (N)
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Force (lbf)
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Force (kgf)
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Force Calculator (F = ma) by TheCalcTools

How the Force Calculator (F = ma) works

Enter the mass in kilograms and the acceleration in metres per second squared.

Newton’s second law says net force equals mass times acceleration.

Weight is the force of gravity: mass times 9.80665.

The formula

F = m × aW = m × g

Worked example

Using the default values shown in the calculator:

Mass (kg)75
Acceleration (m/s²)2
  1. F = 75 × 2 = 150 N.
  2. The same person’s weight on Earth is 735.50 N.

Result:

Force (N)150.00
Weight on Earth (N)735.50
Force (lbf)33.72
Force (kgf)15.30

Frequently asked questions

What is the difference between mass and weight?

Mass is the amount of matter and does not change. Weight is the gravitational force on it, which depends on the planet.

What is a newton?

The force that accelerates 1 kg at 1 m/s².

Sources and further reading

Acceleration CalculatorFind acceleration from a change in speed over time Kinetic Energy CalculatorHow much energy does a moving object carry? Inclined Plane CalculatorFind what happens to a block on a ramp Terminal Velocity CalculatorHow fast does a falling object end up going? Speed, Distance and Time CalculatorPick what you want to find and enter the other two values Projectile Motion CalculatorFind how far and how high a launched object travels

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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.