Your weight on other planets

Here's what a 150 lb person would see on a scale:

Place	Gravity vs. Earth	150 lb on Earth reads
Mercury	0.378	57 lb
Venus	0.903	135 lb
Earth	1	150 lb
Moon	0.165	25 lb
Mars	0.380	57 lb
Jupiter	2.64	396 lb
Saturn	1.14	171 lb
Uranus	0.918	138 lb
Neptune	1.15	173 lb
Pluto	0.063	9.5 lb
Sun	28	4,200 lb

The calculator also covers Jupiter's moons Io, Europa, Ganymede and Callisto, Saturn's moon Titan, and Pluto's moon Charon.

Your mass, the amount of matter in your body, is the same everywhere. Your weight is the force gravity pulls on that mass with, so it changes with the local gravity.

A bathroom scale is calibrated for Earth's gravity: it measures the force and shows it as pounds (or kilograms). Take it to the Moon and it reads about a sixth of what it shows at home, even though you haven't lost an ounce.

The detailed result shows three numbers for the selected body:

• what the scale would show,
• the surface gravity in m/s² and as a multiple of Earth's,
• the actual force in newtons, the scientific unit of weight. A 150 lb (68 kg) person weighs about 668 N on Earth and about 110 N on the Moon.

Planet and Sun values are based on NASA planetary data. For the moons, gravity is calculated from NASA's mass and radius data using g = G·M / R². For the giant planets, published figures vary because they spin so fast: values that include the effect of rotation at the equator come out lower than the ones used here, so other sites may show somewhat different numbers for Jupiter and Saturn.

Jupiter, Saturn, Uranus and Neptune have no solid surface. Their values refer to the altitude where the atmospheric pressure is 1 bar, about the same as at sea level on Earth. Standing there isn't possible, but it is the standard reference level. The Sun's value is at its visible surface (the photosphere) and is purely theoretical. Its bar isn't drawn to scale, or the others would be invisible.

The tool is a quick way to make gravity tangible for students:

1. Have everyone enter their own weight (or a classroom object's) and list their weight on each planet.
2. Ask why Mercury and Mars give almost the same result despite their different sizes.
3. Use the newton value to connect weight to force: weight (N) = mass (kg) × gravity (m/s²).
4. Switch to Moons and compare Ganymede, the largest moon in the solar system, with our Moon.

• On Mars you'd weigh about 38% of your Earth weight, nearly the same as on Mercury, even though Mercury is much smaller. Mercury is dense, with a large iron core.
• Uranus is about 14.5 times as massive as Earth, yet gravity at its cloud tops is a little weaker than Earth's because the planet is so wide.
• Saturn has about 95 times Earth's mass, but its gravity at the cloud tops is in the same range as Earth's, again because of its huge size.
• Titan is the only moon with a thick atmosphere; its gravity is about 14% of Earth's, a little less than our Moon's.

The calculator runs in your browser. Try your pet's weight too, or a car's: the ratios work for anything.