Gravitational Force Calculator

This calculator finds the gravitational force between two objects using Newton's law of universal gravitation, one of the most far-reaching ideas in all of science. Newton's insight was that every mass in the universe attracts every other mass, with a force that depends on both masses and the distance between them. The force is proportional to the product of the two masses and inversely proportional to the square of the distance, so doubling the distance quarters the force. The constant that ties it together is the universal gravitational constant, an extremely small number, which is why gravity is only noticeable when at least one of the masses is enormous, like a planet or a star. The same law explains the weight you feel standing on Earth, the Moon's orbit, the tides, and the motion of planets and galaxies. This tool computes the force for any two masses. You enter the two masses in kilograms and the distance between their centres in metres, and the calculator returns the gravitational force in newtons, along with the acceleration that force produces on the second mass. Scientific notation is supported, so you can enter very large or very small values, such as the mass of the Earth. The results update as you type, letting you explore how mass and distance shape the force. Use it for physics homework, for orbital and astronomical problems, or to see why gravity dominates on cosmic scales yet is negligible between everyday objects. As a check, putting in the mass and radius of the Earth and the mass of a person returns very nearly that person's weight, since weight is simply Earth's gravitational pull.

F = G x m1 x m2 / r squared, with G = 6.674 x 10^-11. Distance is between the centres of mass. Scientific notation (e.g. 5.972e24) is supported.