Why is gravity lower on Mars?

Mars has about a tenth of Earth's mass and about half its diameter. Less mass means less gravitational pull at the surface — 3.72 m/s² versus Earth's 9.81 m/s².

What would you weigh on Mars?

Weight is a mood. Mass is a fact.

Mass is how much of you there is — the same number everywhere in the universe. Weight is the force gravity exerts on that mass, so it changes wherever gravity does. Mars, with a tenth of Earth's mass packed into half its diameter, manages a surface pull of 3.72 m/s² against Earth's 9.81. Multiply your weight by 0.379 and you have your Mars reading.

The consequences are excellent. On Mars you could jump nearly three times higher. You could dunk. A grown adult could carry another grown adult around like groceries. Olympic records would all fall on the first afternoon — though in fairness, the athletes would be wearing pressure suits, which the IOC has yet to rule on.

Around the solar system

World	Gravity vs Earth	150 lb person weighs
Moon	16.6%	25 lb
Mars	37.9%	57 lb
Venus	90.4%	136 lb
Earth	100%	150 lb
Jupiter	253%	380 lb

A kid who just learned they'd weigh 30 pounds on Mars will want the rest of the story — Rusty the Rover tells it in personalized letters, first one free. Rusty weighs 899 kg on Earth and describes himself as "big-boned."

Quick answers

How much would I weigh on Mars?

Your Earth weight × 0.379. A 150 lb person weighs about 57 lb; a 40 kg kid weighs about 15 kg.

Why is Mars's gravity so low?

Gravity at a surface depends on the planet's mass and radius. Mars has ~10.7% of Earth's mass at ~53% of its diameter, which nets out to 38% of the pull.

Could humans live in 38% gravity?

Unknown long-term — it's one of the genuinely open questions of Mars settlement. Astronauts in zero-g lose bone and muscle; whether 38% is enough to stay healthy is something nobody has tested yet.

More instruments: your age on Mars · how long is a day on Mars?