Planet Weight Calculator
Your Weight on Other Worlds
How Planetary Weight Works
Weight is the force of gravity acting on an object's mass, calculated as W = m x g, where m is mass and g is the gravitational acceleration at a body's surface. Each planet, moon, and star has a different surface gravity determined by its mass and radius. According to NASA's Planetary Fact Sheet, surface gravity varies enormously across our solar system — from just 0.063 times Earth's gravity on Pluto to 27.9 times Earth's gravity on the Sun.
Your mass — the total amount of matter in your body measured in kilograms — stays constant no matter where you travel in the universe. However, your weight — the gravitational force you experience — changes with location. A 70 kg person weighs 686 Newtons (154 lbs) on Earth but only 114 Newtons (26 lbs) on the Moon, where gravity is approximately one-sixth of Earth's. On Jupiter, the same person would weigh 1,621 Newtons (365 lbs). According to the European Space Agency, astronauts on the International Space Station experience microgravity (approximately 0.001g) because they are in continuous free fall, not because gravity is absent.
Understanding weight differences between planets is more than an academic exercise. NASA's planned Artemis Moon missions and future Mars colonization efforts require detailed knowledge of how reduced gravity affects human physiology, structural engineering, and equipment design. This calculator lets you instantly see your weight on all eight planets, the Moon, Pluto (now classified as a dwarf planet), and the Sun using the gravity ratios published by NASA.
The Weight Calculation Formula
Surface gravity is calculated from Newton's law of universal gravitation: g = G x M / R^2, where G is the gravitational constant (6.674 x 10^-11 N m^2/kg^2), M is the body's mass, and R is its radius. Your weight on another body is: W_planet = W_earth x (g_planet / g_earth), where the ratio (g_planet / g_earth) is the surface gravity multiplier used in this calculator.
Worked example: You weigh 70 kg on Earth (g = 9.81 m/s^2). Mars has a surface gravity of 3.72 m/s^2, which gives a gravity ratio of 3.72/9.81 = 0.379. Your weight on Mars = 70 x 0.379 = 26.5 kg. On Jupiter (gravity ratio 2.364), your weight = 70 x 2.364 = 165.5 kg. On the Moon (gravity ratio 0.166), you weigh just 11.6 kg and could jump approximately 6 times higher than on Earth.
Key Terms You Should Know
- Mass — The quantity of matter in an object, measured in kilograms. Mass is a fundamental property that does not change regardless of location. A 70 kg person has 70 kg of mass on Earth, Mars, or floating in deep space.
- Weight — The force of gravity acting on an object's mass, measured in Newtons (or commonly expressed in kg or lbs for everyday use). Weight varies with the strength of gravitational acceleration at your location.
- Surface Gravity (g) — The gravitational acceleration experienced at a body's surface. Earth's surface gravity is 9.81 m/s^2 (often rounded to 9.8 or 10). Larger, denser bodies have higher surface gravity.
- Gravitational Constant (G) — The fundamental constant in Newton's law of gravitation, equal to 6.674 x 10^-11 N m^2/kg^2. It determines the strength of gravitational attraction between any two masses in the universe.
- Microgravity — An environment where gravitational effects are near zero, such as aboard the ISS. Astronauts are not weightless because gravity is absent — they are in continuous free fall around the Earth, experiencing approximately 90% of surface gravity but feeling nearly zero net force.
Surface Gravity Across the Solar System
The following table shows the surface gravity multiplier, actual surface gravity, and weight of a 70 kg (154 lb) person on every major solar system body. Data is sourced from NASA's National Space Science Data Center.
| Body | Gravity Multiplier | Surface Gravity (m/s^2) | 70 kg Person Weighs |
|---|---|---|---|
| Mercury | 0.378x | 3.70 | 26.5 kg |
| Venus | 0.907x | 8.87 | 63.5 kg |
| Earth | 1.000x | 9.81 | 70.0 kg |
| Moon | 0.166x | 1.62 | 11.6 kg |
| Mars | 0.377x | 3.72 | 26.4 kg |
| Jupiter | 2.364x | 24.79 | 165.5 kg |
| Saturn | 1.064x | 10.44 | 74.5 kg |
| Uranus | 0.889x | 8.87 | 62.2 kg |
| Neptune | 1.125x | 11.15 | 78.8 kg |
| Pluto | 0.063x | 0.62 | 4.4 kg |
| Sun | 27.9x | 274.0 | 1,953 kg |
Practical Examples
Example 1 — Moon Jump Height: On Earth, an average person can jump about 0.5 meters (20 inches). Since the Moon's gravity is 0.166x Earth's, you could jump approximately 0.5 / 0.166 = 3.0 meters (about 10 feet) on the Moon. Apollo astronauts famously demonstrated this with their bouncing gait, though their bulky spacesuits limited their actual jumping ability. Use our Light Year Calculator to see how far the Moon is in light-seconds (about 1.3).
Example 2 — Mars Colony Considerations: A 70 kg astronaut weighs only 26.4 kg on Mars (0.377g). While this makes lifting heavy equipment easier, long-term exposure to reduced gravity causes bone density loss of 1-2% per month and muscle atrophy. NASA studies show astronauts on the ISS (microgravity) must exercise 2 hours daily to minimize these effects. Mars gravity may require similar countermeasures, though 0.38g may be sufficient to slow degradation significantly compared to microgravity.
Example 3 — Jupiter's Crushing Gravity: A 70 kg person would weigh 165.5 kg on Jupiter (2.364g). Your legs and cardiovascular system, adapted for 1g, would struggle under this load. Walking would feel like carrying nearly 100 kg on your back. Athletes who can squat double their body weight are essentially training for Jupiter-level gravity loading. You can see how your weight compares to a healthy range using our BMI Calculator.
Tips and Interesting Facts
- Saturn could float in water (theoretically). Despite being the second-largest planet, Saturn's average density (0.687 g/cm^3) is less than water (1.0 g/cm^3). Its surface gravity (1.064g) is surprisingly close to Earth's because its enormous radius counterbalances its low density.
- Venus is Earth's gravity twin. At 0.907g, Venus has the closest surface gravity to Earth of any planet. However, its 900 degrees F surface temperature and crushing 90-atmosphere pressure make it the least hospitable "twin" imaginable.
- Neutron stars have extreme gravity. While not in our calculator, a neutron star can have surface gravity 200 billion times Earth's. A teaspoon of neutron star material would weigh about 6 billion tons on Earth.
- Gravity affects time. Einstein's general relativity shows that stronger gravity slows time. GPS satellites must correct for this effect — clocks on satellites (weaker gravity) tick about 45 microseconds faster per day than clocks on Earth.
- Escape velocity varies dramatically. To leave Earth, you need 11.2 km/s. To leave the Moon, only 2.4 km/s. To leave Jupiter, 59.5 km/s. This is why launching rockets from smaller bodies requires far less fuel.
This calculator is for informational purposes only. Gravity values are based on NASA published data and may differ slightly from other sources due to measurement updates.
Frequently Asked Questions
Why does my weight change on different planets?
Your weight changes because each planet has a different surface gravity, which depends on the planet's mass and radius. Weight equals mass times gravitational acceleration (W = m x g). A larger, denser planet pulls on you with more force, making you heavier. A smaller or less dense body has weaker gravity, making you lighter. Your mass (the amount of matter in your body) stays exactly the same everywhere — only the gravitational force acting on that mass changes. Earth's surface gravity is 9.81 m/s^2, which we define as 1g.
What is the difference between mass and weight?
Mass is the quantity of matter in an object, measured in kilograms, and it remains constant regardless of location. Weight is the gravitational force acting on that mass, technically measured in Newtons but commonly expressed in kilograms or pounds for everyday use. A 70 kg person always has 70 kg of mass whether on Earth, Mars, or floating in deep space. However, their weight (the force they exert on a scale) is 686 Newtons on Earth, 260 Newtons on Mars, and essentially zero in orbit. This distinction is crucial in physics and space science.
What would living in Mars gravity feel like?
Mars has surface gravity of 0.38g, meaning you would weigh about 38% of your Earth weight. Walking would feel noticeably lighter and easier, and you could jump roughly 2.6 times higher than on Earth. However, long-term exposure to reduced gravity has significant health implications. NASA research from the ISS shows that microgravity causes bone density loss of 1-2% per month, muscle atrophy, cardiovascular deconditioning, and fluid shifts to the head. While 0.38g is significantly more than microgravity and may slow these effects, exercise countermeasures would likely still be essential for Mars colonists.
Which planet has gravity most similar to Earth?
Venus has the closest surface gravity to Earth at 0.907g, meaning you would weigh about 91% of your Earth weight — barely noticeable in terms of physical sensation. Saturn is the next closest at 1.064g (you would weigh about 6% more than on Earth), followed by Uranus at 0.889g. Interestingly, despite being much larger than Earth, Saturn's low density (it could theoretically float on water) keeps its surface gravity surprisingly Earth-like. Neptune at 1.125g is also relatively close to Earth's gravity.
Could a human survive Jupiter's gravity?
Jupiter's surface gravity of 2.364g would make a 70 kg person feel as if they weighed about 165 kg. While trained fighter pilots can tolerate sustained accelerations of 5-9g for short periods, living at 2.36g would place enormous chronic stress on the heart, lungs, spine, and joints. Standing upright would be exhausting, and everyday tasks would require extreme effort. Additionally, Jupiter has no solid surface — it is a gas giant with atmospheric pressure increasing to crushing levels deep inside. Human survival on Jupiter is physically impossible for multiple reasons beyond just gravity.
How do astronauts deal with weightlessness in space?
Astronauts on the International Space Station experience microgravity (near-weightlessness) and must exercise approximately 2 hours per day using specialized equipment including a treadmill, stationary bike, and resistance exercise device. Despite these countermeasures, astronauts still experience bone density loss, muscle atrophy, vision changes, and cardiovascular deconditioning during long missions. After 6 months on the ISS, astronauts can lose 10-20% of their bone density in weight-bearing bones. Recovery after returning to Earth takes months. Use our BMI Calculator to understand how body composition metrics work under Earth gravity conditions.