About the Gravitational Force Calculator
Every object with mass pulls on every other object. The pull is tiny for everyday things but huge for planets. This calculator uses Newton's law of universal gravitation to find the force between two masses at a given distance. Because the answers can be very small or very large, it shows them in scientific notation as well as in plain numbers. Type the two masses and the distance between their centres and the gravitational force appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Gravitational Force Calculator
- 1Enter the two masses and the distance between their centres.
- 2Pick the units or options from the menus if the gravitational force tool offers them.
- 3Read the gravitational force in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the gravitational force
Students use the law to see where weight comes from. Writers use it to compare pulls in science fiction. Astronomy fans use it to understand tides, orbits and why the Moon stays in orbit around the Earth.
The force falls with the square of the distance: twice as far, a quarter of the force. It is always attractive, and the two bodies pull with equal and opposite forces, so the Earth pulls on you just as hard as you pull on the Earth.
How the gravitational force is worked out
F = G × m1 × m2 ÷ r², where G = 6.6743 × 10⁻¹¹ N·m²/kg². Two masses of 1,000 kg that are one metre apart attract each other with 6.67 × 10⁻⁵ newtons, about the weight of a few grains of sand. A 70 kg person and the Earth, 6,371 km from its centre, pull each other with 687 N. The Earth and the Moon pull with 1.98 × 10²⁰ N.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- Scientific notation
- Plain-number display
- Any masses and distances
Mistakes to avoid with gravitational force
The distance must be measured between the centres of the masses, so for a person on the ground, use the Earth's radius, not the height. The law treats the bodies as points or as spheres; for odd shapes close together it is only an approximation.
On phone and computer
On a phone, type into the boxes one after another and read the gravitational force underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the gravitational force move. The gravitational force calculator works the same on both. Use Weight on Other Planets Calculator for body weight, Orbital Period Calculator for circling bodies, Escape Velocity Calculator for leaving a planet, and Force Calculator for everyday pushes.
Features
- Distance between centres
- Inverse square law
- Forces are equal and opposite
- Clear messages when the gravitational force inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate gravitational force?
F = G × m1 × m2 ÷ r², where G = 6.6743 × 10⁻¹¹ N·m²/kg². Two masses of 1,000 kg that are one metre apart attract each other with 6.67 × 10⁻⁵ newtons, about the weight of a few grains of sand. A 70 kg person and the Earth, 6,371 km from its centre, pull each other with 687 N. The Earth and the Moon pull with 1.98 × 10²⁰ N.
What is the formula for gravitational force?
F = G × m1 × m2 ÷ r², where G = 6.6743 × 10⁻¹¹ N·m²/kg². The gravitational force calculator applies it exactly and rounds only the displayed answer to six significant figures.
Why don't we feel the pull of nearby objects?
Because it is extremely small compared with the pull of the Earth. A one-tonne car at one metre pulls with about a hundred-thousandth of a newton.
What is G?
The gravitational constant, 6.6743 × 10⁻¹¹ N·m²/kg². It was first measured by Cavendish in 1798.
How does this relate to weight?
Weight is the gravitational pull of the planet on you, so it follows the same law with the planet's mass and radius.
Is this gravitational force calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.