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Gravity calculator
Calculate weight on a planet or the gravitational force between any two masses.
Universal Gravity
F = GMm/r² · Force · Mass · Distance
Weight: F = m × g | Universal: F = G × M × m / r²
About the Gravity calculator
Calculate weight on a planet or the gravitational force between any two masses.
How to use the Gravity calculator
- Choose a Calculation Mode: Weight (F = mg) or Universal (F = GMm/r²).
- Enter the Mass and Gravity, or Mass 1, Mass 2 and Distance.
- Press Calculate.
Formula and method
Weight: F = m × g. Universal gravitation: F = G × M × m ÷ r², with G = 6.674 × 10⁻¹¹ N·m²/kg².
Worked example
A 70 kg person weighs 70 × 9.81 = 686.7 N on Earth. Two 1 kg masses 1 m apart attract each other with only 6.674 × 10⁻¹¹ N.
Tips
- Doubling the distance cuts the force to a quarter.
- Gravity on the Moon is about 1.62 m/s².
Frequently asked questions
Does weight change on other planets?
Yes. Your mass stays the same, but weight depends on the local gravity.