Force Calculator

1. Enter any two of force, mass and acceleration.
2. Leave the one you want to find blank.
3. Read the result.
4. See which value was solved for and the formula used.

Here is what each result means:

A force is a push or a pull that can change how something moves. Newton second law says the net force on an object equals its mass times its acceleration, written F equals m a. So the same force accelerates a light object more than a heavy one, and a bigger force gives a bigger acceleration.

In SI units, force is measured in newtons, where one newton accelerates one kilogram at one meter per second squared. Force underlies almost all of mechanics, from a falling apple to a launching rocket. This calculator links force, mass and acceleration so you can find any one from the other two.

The law also explains why heavier vehicles need stronger brakes and longer distances to stop. Stopping means producing a negative acceleration, and a larger mass needs a larger force to change its motion by the same amount. The same push that quickly stops a bicycle barely slows a loaded truck, exactly as F equals m a predicts.

It rearranges Newton second law to solve for whichever value you leave blank.

1. For force, multiply mass by acceleration.
2. For mass, divide force by acceleration.
3. For acceleration, divide force by mass.

Acceleration is a change in velocity over time, and mass ties to weight through gravity; the kinetic energy calculator and density calculator use the same mass.

A 10 kilogram mass accelerates at 2 meters per second squared.

Calculation: F = m a = 10 x 2 = 20 newtons. To find the acceleration a 50 newton force gives that same mass, divide: 50 over 10 is 5 meters per second squared.

One law, rearranged three ways for whatever you need.

All three come from the single relation F equals m a, so knowing any two gives the third.

These related ideas are easy to mix up.

Weight is itself a force, equal to mass times gravity. This calculator handles any force, of which weight is one example.

The Mass

A larger mass needs a larger force for the same acceleration, since force scales with mass.

The Acceleration

A bigger change in motion needs more force. Doubling the acceleration doubles the force.

Net Versus Applied

The law uses the net force, the sum of all forces. Friction and other forces reduce the net that accelerates the object.

Physics Homework

Solve for force, mass or acceleration in a mechanics problem.

Engineering

Estimate the force to accelerate a load, or the acceleration a force produces.

Everyday Motion

Reason about how hard you must push to move or stop something.

1. Using Weight for Mass

Mass is in kilograms; weight is a force in newtons. Do not enter a weight where mass belongs.

2. Forgetting Net Force

The law uses the net force. Subtract friction and opposing forces first.

3. Mixed Units

Use consistent units, ideally SI: newtons, kilograms and meters per second squared.

4. Zero in a Divisor

Solving for mass or acceleration cannot divide by zero.

5. Confusing Force and Energy

Force is a push; energy is force times distance. They are different quantities.

The law is exact; only the displayed decimals are rounded.

It states that the net force on an object equals its mass times its acceleration, written F equals m a. A bigger force gives more acceleration, and a heavier object accelerates less for the same force.

Multiply the mass by the acceleration. A 10 kilogram mass accelerating at 2 meters per second squared needs a force of 10 times 2, which is 20 newtons.

Divide the force by the mass. Leave the acceleration field blank and enter force and mass, and the calculator solves for it.

Divide the force by the acceleration. Leave the mass field blank and enter force and acceleration to solve for the mass.

A newton is the SI unit of force. One newton is the force that accelerates a one kilogram mass at one meter per second squared.

Weight is a force, the pull of gravity on a mass, equal to mass times gravitational acceleration. This calculator handles any force, and weight is one example of it.

Yes. F equals m a uses the net force, the sum of all forces acting. Subtract friction and other opposing forces to get the net that accelerates the object.

SI units are simplest: newtons for force, kilograms for mass, and meters per second squared for acceleration. Keep them consistent for a correct result.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Newton's laws of motion (Wikipedia).
• Force explained (Maths Is Fun).
• Newton (unit) (Wikipedia).