Force Calculator (F = m·a)
Find force from mass and acceleration (Newton's second law).
Result
Force (N)
98.10
How it works
Newton's second law states that force equals mass times acceleration: F = m·a, in newtons. Push a 10 kg crate at 2 m/s² and you are applying 20 N. Read the formula backwards and it becomes a statement about inertia: a = F/m. For a given push, acceleration is inversely proportional to mass — which is why the same shove barely budges a car but sends a shopping trolley flying. Mass is precisely the measure of how stubbornly an object resists having its motion changed. What matters is the net force, the sum of everything acting at once. A crate pushed with 100 N against 100 N of friction has zero net force and does not accelerate at all, even though two large forces are present. That is the whole content of the first law: no net force, no change in motion.
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Frequently asked questions
What is Newton's second law?
Force = mass × acceleration (F = m·a).
What is 1 newton?
The force that accelerates 1 kg at 1 m/s².
What is the difference between mass and weight?
Mass is the amount of matter, in kilograms, and never changes. Weight is a force — mass times local gravity, in newtons — so the same 70 kg body weighs about 686 N on Earth and roughly a sixth of that on the Moon.
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