Weight on Planets Calculator

Weight on Other Planets Calculator

Compare how an Earth weight would scale on major solar-system bodies using relative surface gravity. This calculator returns Earth-weight equivalents in the same unit you enter.

Uses relative surface gravity (Earth = 1.000)

Enter a positive number. Results stay in the same unit as the input (kg).

Important: this calculator scales an Earth weight by gravity ratio. If you enter 70 kg, the outputs are kg-equivalent values commonly used in everyday discussions, not direct SI force values. True force in Newtons is shown only when the input unit is kg.
Jupiter Equivalent
165.48
kg-equivalent (2.364× Earth)
Lightest Here
4.69
Pluto
Jupiter / Pluto
35.3×
N on Earth
686.47

Earth-Weight Equivalents on Each Body

Mercury
26.46
0.378× Earth
Venus
63.49
0.907× Earth
Earth
70.00
1.000× Earth
Moon
11.62
0.166× Earth
Mars
26.39
0.377× Earth
Jupiter
165.48
2.364× Earth
Reference-pressure level only; no solid surface.
Saturn
64.12
0.916× Earth
Reference-pressure level only; no solid surface.
Uranus
62.23
0.889× Earth
Reference-pressure level only; no solid surface.
Neptune
78.75
1.125× Earth
Reference-pressure level only; no solid surface.
Pluto
4.69
0.067× Earth

What This Calculator Does

This calculator uses published relative surface gravity values to scale an Earth weight to other solar-system bodies. The core idea is simple: if a body's surface gravity is 0.378 times Earth's, then an object that weighs 70 on Earth would have an Earth-weight equivalent of 26.46 there.

That is useful for intuition, but it is important to be precise about units. In everyday speech, people often say “I weigh 70 kg” or “I weigh 154 lb,” even though kilograms measure mass and pounds can refer either to mass or force depending on context. This component follows the everyday comparison model: it preserves the input unit and scales it by gravity ratio. It therefore reports weight-equivalent values, not pure SI force unless you convert separately.

Gas giants need an extra caveat. Jupiter, Saturn, Uranus, and Neptune do not have solid surfaces like Earth or Mars. Their listed “surface gravity” is defined at a reference level in the atmosphere, typically near the 1-bar pressure level. So the scaling is mathematically meaningful as a gravity comparison, but not a realistic standing weight for a person.

Formulas

Scaled Earth-weight equivalent: W_scaled = W_earth × (g_body / g_earth)
True force when mass is known in kilograms: F = m × g
Newtonian surface gravity: g = GM / R²
Here, G is the gravitational constant, M is the body's mass, and R is radius measured from the body's center to the reference surface.

Worked Example

Example: 70 kg on Earth

Suppose a person has a mass of 70 kg on Earth. Their Earth weight force is:

F_Earth = m × g = 70 × 9.80665 ≈ 686.47 N
Moon equivalent = 70 × 0.166 = 11.62 kg-equivalent
Mars equivalent = 70 × 0.377 = 26.39 kg-equivalent
Jupiter equivalent = 70 × 2.364 = 165.48 kg-equivalent

If you want true force in Newtons on Mars instead of a kg-equivalent value, use the force formula with Mars gravity:

F_Mars = 70 × (0.377 × 9.80665) ≈ 258.68 N

The two ways of writing the result describe the same comparison in different units. The kg-equivalent format is intuitive for casual readers; the Newton value is the physically correct force unit.

Frequently Asked Questions

What is the difference between mass and weight?

Mass measures how much matter an object has. Weight is the force caused by gravity acting on that mass. Mass stays the same from place to place; weight changes when gravity changes.

Why is Jupiter not hundreds of times stronger than Earth?

Surface gravity depends on both mass and radius. Jupiter is much more massive than Earth, but it is also much larger, so the greater distance from its center reduces the surface gravity compared with what mass alone would suggest.

Why is Saturn less than 1× Earth gravity?

Saturn is very massive, but it also has a very large radius and low average density. At the reference level used for “surface gravity,” those factors bring the gravity close to Earth’s rather than far above it.

Are the gas-giant results physically usable?

Only as gravity comparisons. Jupiter, Saturn, Uranus, and Neptune do not offer a walkable solid surface, so these values are not realistic standing weights for a person or machine.

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