How the Planetary Weight Calculator Works
Your weight depends on where you are. On the Moon you would feel much lighter, and on Jupiter you would feel crushed. This is because weight is the pull of gravity on your body, and every planet and moon pulls with a different strength. The Planetary Weight Calculator shows what you would weigh on each world in our solar system.
Mass and weight are not the same
- Mass is the amount of matter in your body. It stays the same everywhere. It is measured in kilograms or pounds.
- Weight is the force of gravity pulling on that mass. It changes from place to place. In science it is measured in newtons (N).
In daily life, people say "weight" and give a number in kilograms or pounds. That number is really the mass, and a bathroom scale is set up to show it on Earth. That is why the calculator gives both: the weight force in newtons, and the number that a scale would show on that world.
What you enter
- Your mass, in kilograms or in pounds.
- The planet or moon where you want to know your weight.
How the results are worked out
weight force (N) = mass (kg) x surface gravity (m/s²) scale reading = mass x gravity there / gravity on Earth
The surface gravity of each world is the acceleration that gravity gives to a falling object. On Earth it is 9.81 m/s². If you enter pounds, the calculator first turns them into kilograms, because newtons need kilograms.
Gravity depends on how heavy a world is and how big it is: g = G x M / r², where M is the mass of the world, r is its radius, and G is the gravitational constant. A big world pulls harder, but you are also farther from its center, and the pull falls with the square of the distance. For Mars, M is 6.417 x 10^23 kg and r is 3,390 km, which gives 3.73 m/s².
The gravity of each world
| World | Gravity (m/s²) | Compared with Earth |
|---|---|---|
| Mercury | 3.70 | 37.7% |
| Venus | 8.87 | 90.4% |
| Earth | 9.81 | 100% |
| The Moon | 1.62 | 16.5% |
| Mars | 3.72 | 37.9% |
| Jupiter | 24.79 | 252.7% |
| Saturn | 10.44 | 106.4% |
| Uranus | 8.69 | 88.6% |
| Neptune | 11.15 | 113.7% |
| Pluto | 0.62 | 6.3% |
Jupiter, Saturn, Uranus and Neptune are giant planets with no solid ground. Their gravity is given at the level in their atmosphere where the pressure equals 1 bar, which is about the pressure at the surface of the Earth. The values are rounded, and different sources give slightly different numbers.
A worked example
You have a mass of 70 kg. On Mars, the gravity is 3.72 m/s².
| Step | Result |
|---|---|
| Weight force on Mars (70 x 3.72) | 260.4 N |
| Weight force on Earth (70 x 9.81) | 686.7 N |
| Share of your Earth weight (3.72 / 9.81) | 37.9% |
| A scale would read (70 x 3.72 / 9.81) | 26.54 kg |
On Mars, you would weigh only about 38% of what you weigh at home. A person of 154 pounds would see about 58 pounds on the scale.
Your weight on every world (70 kg)
| World | Weight force | A scale would read |
|---|---|---|
| Mercury | 259.0 N | 26.40 kg |
| Venus | 620.9 N | 63.29 kg |
| Earth | 686.7 N | 70.00 kg |
| The Moon | 113.4 N | 11.56 kg |
| Mars | 260.4 N | 26.54 kg |
| Jupiter | 1,735.3 N | 176.89 kg |
| Saturn | 730.8 N | 74.50 kg |
| Uranus | 608.3 N | 62.01 kg |
| Neptune | 780.5 N | 79.56 kg |
| Pluto | 43.4 N | 4.42 kg |
Chart: what the scale would read
A person of 70 kg, on each world. Each block is about 4.4 kg.
Mercury ██████ 26.4 kg Venus ██████████████ 63.3 kg Earth ████████████████ 70.0 kg Moon ███ 11.6 kg Mars ██████ 26.5 kg Jupiter ████████████████████████████████████████ 176.9 kg Saturn █████████████████ 74.5 kg Uranus ██████████████ 62.0 kg Neptune ██████████████████ 79.6 kg Pluto █ 4.4 kg
Only on Jupiter would you feel more than 2 times as heavy as on Earth. On the Moon you would feel about a sixth of your weight.
How high could you jump?
If you push off the ground with the same speed everywhere, the height of your jump is proportional to 1 divided by gravity. A jump of 0.5 m on Earth would reach:
| World | Jump height |
|---|---|
| Jupiter | 0.20 m |
| Earth | 0.50 m |
| Mars | 1.32 m |
| Mercury | 1.33 m |
| The Moon | 3.03 m |
| Pluto | 7.91 m |
Jupiter █ 0.20 m Earth ███ 0.50 m Mars ███████ 1.32 m Mercury ███████ 1.33 m Moon ███████████████ 3.03 m Pluto ████████████████████████████████████████ 7.91 m
This is a simple estimate. A space suit is heavy, and it would make the jump much lower.
Fun facts
- Your mass would be the same on every world. Only your weight changes.
- The Sun's gravity is about 28 times that of Earth at its surface, but no one can stand on it.
- Astronauts on the Moon could carry heavy equipment, because it weighed only a sixth as much.
- Venus and Uranus both pull with about 90% of the gravity of Earth, although Venus is a rocky planet and Uranus is an ice giant.
What this calculator does not include
- The small changes in gravity with height, latitude and depth on any one world. On Earth, gravity is 9.78 m/s² at the equator and 9.83 m/s² at the poles.
- The effect of the spin of a world, which slightly lowers your weight at its equator.
- Dwarf planets and moons other than the Moon and Pluto, and the Sun.
- Whether you could survive there. Most of these worlds have no air that you can breathe, and very high or low temperatures.
This tool is for education and fun. The gravity values are rounded, and different sources give slightly different figures.