Weight Calculator: W = m × g, Any Planet
Find weight, mass or gravity with W = m·g. Choose Earth, Moon, Mars, Jupiter and more, and see your weight on every planet at once. Free and private in your browser.
2 fields are empty. Fill in all but one.
About the Weight Calculator
The Weight Calculator solves W = m × g, where W is weight, m is mass and g is the gravitational acceleration. Fill in any two of Weight, Mass and Gravitational acceleration and the third appears as you type. A row of presets sets g for Earth, the Moon, Mars, Venus, Jupiter, Saturn, Mercury and the Sun, and a table underneath shows the same mass weighed on every one of them.
Mass and weight are different things. Mass is the amount of matter in an object and is the same everywhere. Weight is the force gravity exerts on that mass, so it changes from place to place. An astronaut keeps the same mass on the Moon but weighs about one sixth as much.
How to use the weight calculator
Steps
- Choose a preset such as Earth or Mars, or type your own gravitational acceleration.
- Enter the mass, or enter the weight if you want to find the mass.
- Pick units. Weight can be shown in newtons (N), kilograms-force (kgf) or pounds-force (lbf), mass in kg, g or lb, and gravity in m/s² or ft/s².
- Read the answer under the formula. Once the mass is known, the planet table lists your weight on every preset.
Mass and gravity must be greater than zero. If all three fields are filled, clear one, and if fewer than two are filled, a hint tells you what is missing.
Formula
Standard gravity on Earth is exactly 9.80665 m/s², and the calculator uses that value for the Earth preset. Weight in newtons is a force, and 1 kgf is the force of one kilogram of mass in standard gravity, 9.80665 N.
Weight of a 70 kg person on each preset
| Body | g (m/s²) | Weight (N) |
|---|---|---|
| Earth | 9.80665 | 686.4655 |
| Moon | 1.62 | 113.4 |
| Mars | 3.72 | 260.4 |
| Venus | 8.87 | 620.9 |
| Jupiter | 24.79 | 1,735.3 |
| Saturn | 10.44 | 730.8 |
| Mercury | 3.7 | 259 |
| Sun | 274 | 19,180 |
These are surface values. Gas giants have no solid surface, so Jupiter and Saturn use the gravity at the level where the pressure is one bar.
Worked examples
Example 1: weight on the Moon
A 70 kg person on the Moon, where g = 1.62 m/s², has W = 70 × 1.62 = 113.4 N. On Earth the same person weighs 686.4655 N, so the Moon weight is about 16.5 percent of the Earth weight.
Example 2: find the mass
A scale reads a weight of 500 N on Earth. The mass is m = 500 ÷ 9.80665 = 50.9858 kg.
Example 3: find the gravity
A 100 kg rover weighs 600 N on an unknown world. Then g = 600 ÷ 100 = 6 m/s², a little over half of Earth's gravity.
Privacy
Nothing is uploaded; every calculation runs in your browser and never leaves your device.
Related tools
Convert your mass first with the Mass Converter, use the Force Calculator when you need F = m × a for a moving object, or switch units of force with the Force Converter.
Frequently asked questions
What is the difference between mass and weight?
Mass is the amount of matter in an object, in kilograms, and is the same everywhere. Weight is the force of gravity on that mass, in newtons, so it changes with the gravity of the place.
How do I calculate weight?
Multiply mass by gravitational acceleration: W = m × g. A 70 kg person on Earth, where g is 9.80665 m/s², weighs 686.4655 N. Choose a preset or type your own gravity.
How much would I weigh on the Moon or Mars?
On the Moon, g is 1.62 m/s², so a 70 kg person weighs 113.4 N, about 16.5 percent of the Earth value. On Mars, g is 3.72 m/s², giving 260.4 N. The table under the calculator shows every preset at once.
Which gravity values do the presets use?
Earth 9.80665, Moon 1.62, Mars 3.72, Venus 8.87, Jupiter 24.79, Saturn 10.44, Mercury 3.7 and the Sun 274, all in m/s². Gas giants and the Sun have no solid surface, so the values are for the visible cloud top or photosphere.
Can I find mass from weight?
Yes. Fill in weight and gravity and leave mass empty. A weight of 500 N on Earth means a mass of about 50.9858 kg. You can also solve for gravity from weight and mass.
What are kgf and lbf?
A kilogram-force is the weight of one kilogram of mass in standard gravity, 9.80665 N. A pound-force is the weight of one pound of mass in standard gravity, about 4.44822 N. They are listed as weight units next to newtons.
Does the page upload my numbers?
No. The mass, weight and gravity values you enter are calculated locally in your browser, and nothing is uploaded, stored or shared with a server, so your own measurements stay private.