Enter a mass to find its weight — the force of gravity acting on it — on Earth and every other planet and moon.
Enter a mass and click Calculate
This free weight calculator computes weight — the gravitational force acting on a mass — from a mass you enter, showing the result on Earth and every other major planet and the Moon at once. Unlike a simple unit converter, this calculator applies the actual physics relationship between mass and weight, W = mg, using each body's real gravitational acceleration.
Enter your mass in kilograms, and the calculator multiplies it by standard Earth gravity (9.80665 m/s²) to find your weight in newtons, then converts that to pounds-force for convenience. The same mass is also multiplied by the gravitational acceleration of every other planet and the Moon, producing a full comparison table — since mass never changes, but weight scales directly with local gravity.
Physics students learning the mass-versus-weight distinction, space and astronomy enthusiasts curious how much they'd weigh on Mars or the Moon, and educators demonstrating gravity concepts. It's a formula-based educational tool, not a substitute for a calibrated scale.
The physics formula this calculator uses
Weight is simply the force of gravity, calculated using Newton's second law (Force = mass × acceleration) with gravitational acceleration standing in for acceleration.
Each planet and moon has its own gravitational acceleration based on its mass and radius, which is why the same mass produces very different weight readings across the solar system.
Because mass measures the amount of matter, not a force, it doesn't change when you travel to a different gravitational environment — only your weight does.
From entering mass to reading the full planet comparison
Type your mass in kilograms.
See your weight on Earth in newtons and pounds-force.
See your weight on every other planet and the Moon at once, for easy comparison.
Comparing weight on Earth and the Moon for the same mass
Where a mass-to-weight comparison is genuinely fun and useful
Solve weight and gravitational force problems and check your answer against a reliable formula tool.
Find out how much you'd weigh on the Moon, Mars, or Jupiter.
Show students how the same mass produces very different weight readings across the solar system.
Quickly convert a known mass into a weight force in newtons for a physics or engineering calculation.
What this weight calculator does well, and where it has boundaries
Understand mass vs. weight correctly
Summary: This weight calculator converts a mass into weight (gravitational force) on Earth and every other planet and moon at once, using W = mg with standard gravity values — free, instant, and grounded in real physics. Pair it with the Mass Calculator or Density Calculator for related calculations.
Common questions about calculating weight
Space agency and standards references to complement this calculator
Other measurement tools