Your Weight on the Moon, Mars, Jupiter, and More

Type your weight on other planets by entering what the bathroom scale says on Earth. The calculator multiplies that number by each body's surface gravity ratio and hands you a table: Moon, Mars, Jupiter, Saturn, every major world in one glance. If you weigh 150 lb on Earth, you'll see roughly 25 lb on the Moon and 380 lb on Jupiter — same body, wildly different gravitational pull.

Pick pounds or kilograms, hit calculate, and the bar chart fills in. Want to test a made-up exoplanet? Enter a custom gravity value (in m/s² or as a multiple of Earth's g) and the tool adds it to the comparison. The whole thing runs in your browser — no sign-up, no data stored.

Your mass — the amount of matter in your body — stays exactly the same whether you're standing on Mars or floating near Pluto. What changes is weight, the force gravity exerts on that mass. The formula is simple: Weight = Mass × gravitational acceleration. Earth's gravitational acceleration is about 9.81 m/s². The Moon's is 1.62 m/s², roughly one-sixth as strong. Multiply your mass by each planet's number and you get a different scale reading every time.

When the tool says “you weigh 25 kg on the Moon,” it means a scale calibrated for Earth would read 25 kg there. Your mass hasn't shrunk — gravity just pulls less. This single distinction trips up most people, and it's the whole reason the calculator exists: to make the difference between mass and weight something you can feel, not just memorize.

Say you're 70 kg on Earth and curious about every stop on a solar system road trip. Here's what the calculator returns:

Notice that Mercury and Mars share almost the same gravity ratio despite being completely different worlds — Mercury is dense and tiny, Mars is larger but less dense. Saturn, 95 times Earth's mass, barely outweighs Earth's pull at its cloud tops because its radius is enormous. Size alone doesn't decide gravity — mass and radius work together, and this table makes that obvious at a glance.

Swapping mass and weight. If you type 70 thinking kilograms of mass but the tool expects pounds, your results will be off by a factor of 2.2. Check the unit label before you hit calculate.

Assuming “bigger planet = stronger gravity.” Jupiter is 318 times Earth's mass yet only 2.5 times Earth's surface gravity. Its radius is so large that you stand far from the center of mass, weakening the pull. Saturn is even more extreme — nearly 100 Earth masses, but just 1.07 g at the cloud tops because it's puffed up with hydrogen.

Thinking you can “stand on” Jupiter. Gas giants have no solid surface. The gravity number refers to the altitude where atmospheric pressure matches Earth's sea level. You wouldn't be standing — you'd be floating in a thick, crushing atmosphere. The calculator treats it as a surface for comparison purposes, and that's worth knowing before you drop it into a school report.

Ignoring local variation. Gravity isn't perfectly uniform on any world. Earth's own gravitational acceleration ranges from about 9.78 m/s² at the equator to 9.83 m/s² at the poles because the planet bulges and spins. The values in this tool are standard averages — accurate enough for classroom work, not for spacecraft navigation.

Dwarf planets and large moons. Pluto's gravity is 0.063 g — a 70 kg person would weigh under 5 kg. On Titan, Saturn's largest moon, gravity is 0.138 g, which is lower than Earth's Moon. Europa sits at about 0.134 g. These numbers matter if you care about future exploration targets: landing and taking off is cheap in fuel when gravity is that low.

Custom exoplanets. Kepler-442b is a confirmed exoplanet in the habitable zone with an estimated surface gravity around 1.3 g. Plug 12.75 m/s² into the custom field and a 70 kg person becomes 91 kg — heavier than Earth but not crushing. That's the kind of thought experiment that makes orbital discovery personal.

The Sun. Surface gravity is about 274 m/s² — roughly 28 times Earth's. A 70 kg person would “weigh” nearly 1,960 kg. Obviously you'd never survive the heat, but the number is useful for understanding why the Sun holds the entire solar system in orbit.

Asteroids. Ceres, the largest asteroid, has surface gravity around 0.029 g. You could launch yourself into orbit with a running jump. Smaller asteroids have even less — on some, you'd need to tether yourself down to avoid drifting away.

Would I really weigh less on Mars? Yes. A bathroom scale on Mars would show about 38% of your Earth reading. Your body hasn't changed — the planet simply pulls less hard.

What would I weigh on Jupiter if it has no ground? The calculator uses Jupiter's gravity at the 1-bar pressure level (equivalent to Earth's sea-level atmosphere). That's the standard reference altitude for gas giants. You'd be suspended in dense gas, not standing on rock.

Do astronauts actually feel lighter on the Moon? Absolutely. Apollo crews could hop several feet off the ground in 180-pound spacesuits because those suits weighed only about 30 lb in lunar gravity. The footage looks slow-motion partly because they were genuinely bouncing.

Is this accurate enough for homework? For any introductory physics or astronomy class, yes. The gravity ratios come from NASA's Planetary Fact Sheet. For mission-planning precision, engineers use full gravitational models that account for altitude, latitude, and local density.

Once you've compared weights, try the Age on Planets calculator to see how many birthdays you'd have on Mercury (spoiler: a lot) or how long a single Jupiter year lasts in Earth time. Together, the two tools cover the most-asked solar system questions in one sitting.