Why does weight differ from planet to planet?
Weight depends on the gravity of the body you're standing on. Your mass (the amount of matter that makes up your body) stays the same everywhere, but you're measured as heavier on planets with stronger gravity and lighter on ones with weaker gravity. For example, the Moon's gravity is about 1/6 of Earth's, so your weight there would be about 1/6 as much.
How is this calculated?
Each planet's gravity is widely known as a multiple of Earth's (set as 1) β for example, Jupiter is 2.36 times and Mars is 0.38 times. We multiply your entered Earth weight by that multiple to calculate your weight on each planet.
A note on accuracy
Jupiter, Saturn, Uranus, and Neptune are gas giants with no solid surface, so you couldn't actually "stand" on them. This calculation is purely a theoretical one based on each planet's surface gravity.
Frequently Asked Questions
Jupiter is so much bigger than Earth β why is its gravity only 2.36 times as strong?
Gravity depends on both mass and radius (size), not mass alone. Jupiter has enormous mass, but it also has a much larger radius, so its surface gravity multiplier doesn't grow as much as its mass increase alone would suggest.
Why isn't Pluto considered a planet anymore?
In 2006, the International Astronomical Union (IAU) reclassified Pluto as a "dwarf planet" because it hasn't cleared its orbital neighborhood of other debris β one of the three criteria required for full planet status. It's still included here since its gravity is well documented and it remains a familiar reference point.