Weight from Mass Calculator

Weight and mass are different. Mass is the amount of matter in an object and it stays the same everywhere in the universe. Weight is the gravitational force acting on that mass:

W = m × g

Where W is weight in newtons (N), m is mass in kilograms, and g is the surface gravitational acceleration of the celestial body.

On Earth, g = 9.81 m/s². A 70 kg person weighs 70 × 9.81 = 686.7 N (about 154 lbs-force).

Surface gravity of solar system bodies:

• Mercury: 3.70 m/s² (38% of Earth)
• Venus: 8.87 m/s² (90% of Earth)
• Earth: 9.81 m/s²
• Moon: 1.62 m/s² (17% of Earth), where a 70 kg person weighs just 113.4 N
• Mars: 3.72 m/s² (38% of Earth)
• Jupiter: 24.79 m/s² (253% of Earth)
• Saturn: 10.44 m/s² (106% of Earth)
• Uranus: 8.69 m/s² (89% of Earth)
• Neptune: 11.15 m/s² (114% of Earth)

The popular misconception: astronauts in the International Space Station are not weightless because there is no gravity. They are in a continuous free fall, and the station is falling toward Earth just fast enough that Earth curves away beneath it. They feel weightless because everything around them is falling at the same rate. True weightlessness only exists at gravitational equilibrium points in deep space.

Converting newtons to pounds-force: 1 N ≈ 0.2248 lbs-force.

Why your bathroom scale is lying to you, slightly. A scale does not measure mass. It measures the force you press into it and then divides by Earth gravity to print a number in kilograms or pounds. That works perfectly here and nowhere else. Stand on the same scale on the Moon and a 70 kg person reads 11.6 kg, not because they lost anything but because the instrument was calibrated for a planet they are no longer standing on. A balance scale, the old two-pan kind that compares your object against known weights, would read a true 70 kg anywhere in the universe, because gravity divides out of both sides.

This is also why gyms in different countries sell the same dumbbells. A “10 kg” dumbbell is 10 kg of iron everywhere; what changes with location is how hard it pulls on your hand, and Earth’s own gravity varies by about 0.5% between the poles and the equator. You are very slightly heavier in Oslo than in Singapore, and no scale on the market is honest enough to notice.

The chart shows your weight in newtons across the solar system, with your selected body highlighted.