🌍 Gravitational Force Calculator (Newton)
Find the gravitational attraction between two masses (F = Gm₁m₂/r²), or solve for a mass or the separation.
Gravitational force F
198211000000000000000 N
Newton’s law of gravitation: F = G·m₁·m₂/r², with G = 6.6743×10⁻¹¹ N·m²/kg². 🔒 Computed in your browser.
How the gravitational force calculator (newton) works
Newton’s law of universal gravitation: every two masses attract with F = G·m₁·m₂/r², where G = 6.6743×10⁻¹¹ N·m²/kg² and r is the distance between their centres. Enter any three of the four and the tool solves for the last.
G is a fixed CODATA constant. The inverse-square distance means doubling the separation quarters the force. Defaults show the Earth–Moon attraction.
Frequently asked questions
What is Newton’s law of gravitation?
Two masses attract with a force F = G·m₁·m₂/r² — proportional to each mass and inversely proportional to the square of their distance. G is the gravitational constant.
What is the value of G?
The gravitational constant G = 6.6743×10⁻¹¹ N·m²/kg² (CODATA). It’s the same everywhere in the universe.
Why is gravity so weak between everyday objects?
Because G is tiny. Two 1 kg masses 1 m apart attract with only ~6.7×10⁻¹¹ N — imperceptible. Gravity only dominates at astronomical masses.
What does inverse-square mean here?
Force falls off with the square of distance: double the separation and the force drops to a quarter; triple it and it drops to a ninth.
What distance do I use?
The distance between the centres of the two masses (for spheres), not their surfaces.