Planet Weight Calculator Formula

Understand the math behind the planet weight calculator. Each variable explained with a worked example.

Formulas Used

Weight on Planet

planet_weight = earth_weight * gravity_ratio

Force (N)

force_newtons = earth_weight * gravity_ratio * 9.80665

Variables

VariableDescriptionDefault
earth_weightYour Weight on Earth(kg)70
gravity_ratioPlanet Gravity (g)(g)0.38

How It Works

Your Weight on Other Worlds

Weight is the force of gravity on your mass: W = m × g.

W_planet = W_Earth × (g_planet / g_Earth)

Common gravity ratios: Moon 0.17, Mars 0.38, Jupiter 2.53, Saturn 1.07.

Note: mass stays the same everywhere; weight changes with gravity.

Worked Example

A 70 kg person on Mars (g = 0.38).

earth_weight = 70gravity_ratio = 0.38
  1. 01Weight on Mars = 70 × 0.38 = 26.6 kg-force
  2. 02In Newtons: 26.6 × 9.807 = 260.9 N
  3. 03You would feel much lighter on Mars.

Frequently Asked Questions

What is the difference between mass and weight?

Mass (kg) is the amount of matter and is constant everywhere. Weight is the gravitational force on that mass and changes with location.

How much would I weigh on the Moon?

About 17% of your Earth weight. A 70 kg person would feel like 11.9 kg.

Can I weigh more than on Earth?

Yes, on Jupiter (2.53 g) or some exoplanets. A 70 kg person would weigh about 177 kg-force on Jupiter.

Ready to run the numbers?

Open Planet Weight Calculator