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Force Mass calculator
Calculate force, mass, acceleration, weight or impulse using Newton's second law.
Force Mass calculatorForce & Mass
F = ma · Newton's 2nd Law · Weight · Impulse Analysis
F = m × a | W = m × g | Impulse: J = F × t | Momentum: p = m × v
Sometimes the force and the acceleration are what you can measure, and the mass is the mystery: a pushing test on a trolley, a rocket's thrust against its climb. This calculator rearranges Newton's second law to solve for mass (or acceleration) directly.
How to use this calculator
- Enter the net force and the acceleration it produces.
- Press calculate to see the mass.
- Or enter force and mass to get the acceleration instead.
Weighing things you cannot put on scales
The rearrangement m = F/a is how engineers estimate the mass of vehicles from test pushes, and how spacecraft masses are checked from thruster burns. It works precisely because mass is the property that resists acceleration, so the resistance itself becomes the measuring instrument.
Frequently asked questions
How do I find mass from force and acceleration?
Mass = force divided by acceleration (m = F/a), in kilograms when force is in newtons and acceleration in m/s².
Is mass the same as weight?
No. Mass (kg) is the amount of matter and its resistance to acceleration; weight (N) is gravity's force on that mass, and changes with the planet.
Why must the force be the net force?
Because acceleration responds to the sum of all forces. Using only the push while ignoring friction overstates the mass the formula returns.