🪐 Planetary Weight Calculator
Enter your weight on Earth to see what you'd weigh on the Moon and each planet in the solar system, based on their surface gravity relative to Earth's.
How each figure is produced
Every line is one multiplication against a stored surface-gravity ratio, with Earth set to 1:
weight there = weight on Earth × (surface gravity there ÷ Earth’s)
surface gravity g = GM ÷ r²The ratios the page uses are Mercury 0.378, Venus 0.907, Moon 0.166, Mars 0.377, Jupiter 2.36, Saturn 0.916, Uranus 0.889, Neptune 1.12 and Pluto 0.063. So the 150 lb default becomes 24.9 lb on the Moon, 56.5 lb on Mars, 354.0 lb on Jupiter and 9.4 lb on Pluto. Switching the unit to kilograms rescales nothing — the same ratios are applied to whatever number you typed.
Why the numbers fall where they do
- Size alone does not decide it. Mercury and Mars come out almost identical, 0.378 against 0.377, even though Mars is nearly twice the diameter. Mercury is far denser, and the extra mass cancels its smaller radius in GM ÷ r².
- The gas giants have no surface. Jupiter, Saturn, Uranus and Neptune are quoted at the 1-bar cloud-top level at the equator. Both choices matter: rapid rotation flings weight off the equator, so the polar figure for Saturn is meaningfully higher.
- Only three exceed Earth. Jupiter at 2.36 and Neptune at 1.12 are the outliers; Venus, Saturn and Uranus all sit within a tenth of Earth despite being wildly different worlds.
Frequently asked questions
What would I weigh on the Moon?
About one sixth of your Earth weight — the ratio is 0.166, so 150 lb reads as 24.9 lb and 90 kg as 14.9 kg.
Why do I weigh more on Jupiter but not much more?
Jupiter has 318 times Earth’s mass but 11 times its radius, and the radius is squared in the denominator. The two effects nearly cancel, leaving 2.36 rather than the tenfold jump people expect.
Is Pluto really that weak?
Yes. At 0.063 of Earth a 150 lb adult weighs 9.4 lb there, less than a gallon of milk. A gentle jump would carry you several metres and take most of a minute to come down.