Gravitational Force Calculator

About this calculator

This calculator applies Newton's law of universal gravitation, F = G(m₁m₂)/r², where G is the gravitational constant (6.674×10⁻¹¹ N·m²/kg²), to find the attractive force between two masses separated by a given distance.

Physics students use it for mechanics and astronomy homework, and it's the same formula used (in more elaborate form) to calculate orbital mechanics, satellite trajectories, and the gravitational pull between planets and stars. Because the force falls off with the square of distance, the calculator makes it easy to see why doubling the distance between two objects cuts the gravitational force to a quarter, not to a half.