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The Planet Weight Calculator lets you find out how much you would weigh on any planet in the Solar System, as well as on the Moon, Pluto, and the Sun. This is one of the most popular astronomy calculations because it makes the abstract concept of gravity tangible and personal. The answer often surprises people — a 70 kg person would weigh only about 26.5 kg on Mars but a crushing 1,957 kg on the surface of the Sun.
It is important to distinguish between mass and weight. Your mass — the amount of matter in your body — does not change regardless of where you are in the universe. Weight, on the other hand, is a force: it is the product of your mass and the local gravitational acceleration. On Earth, the standard surface gravity is 9.807 m/s². On Mars, it is only 3.721 m/s², roughly 38% of Earth's. On Jupiter, it is 24.79 m/s², about 2.53 times stronger than on Earth.
Surface gravity depends on two factors: the mass of the body and your distance from its center (its radius). Larger planets have stronger gravity, but not always proportionally, because their density varies. Saturn, despite being almost 10 times the diameter of Earth, has a surface gravity only slightly stronger than Earth's because its average density is less than water — it would float in a giant ocean. Conversely, the Sun's gravity is 28 times Earth's despite being much larger, reflecting its enormous mass.
For gas giants like Jupiter, Saturn, Uranus, and Neptune, there is no solid surface — the quoted surface gravity refers to the 1-bar pressure level in the atmosphere, which is used as the reference point. In reality, you could not stand on these planets in any conventional sense.
This calculator is valuable for science education, helping students understand Newton's law of universal gravitation and the relationship between mass, radius, and surface gravity across different worlds. It is also a fun way to appreciate the incredible diversity of gravitational environments in our Solar System, from the feather-light gravity of Pluto to the punishing pull of the Sun.
Weight on another planet is calculated as: W_planet = W_earth x (g_planet / g_earth), where g_earth = 9.807 m/s². Each planet's surface gravity is a well-measured physical constant: Mercury 3.7, Venus 8.87, Mars 3.721, Jupiter 24.79, Saturn 10.44, Uranus 8.87, Neptune 11.15, Moon 1.625, Pluto 0.62, Sun 274 m/s². The gravity ratio shows how many times stronger or weaker gravity is compared to Earth.
A gravity ratio below 1 means you would feel lighter than on Earth — useful to know for hypothetical space habitat design. A ratio above 1 means heavier. Mars at 0.379g is often cited as the threshold below which long-term human habitation may cause significant bone and muscle loss. Jupiter's 2.53g would make movement extremely difficult for a human body adapted to 1g.
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An 80 kg astronaut would weigh just over 30 kg on Mars, making walking and carrying equipment much easier despite the thin atmosphere.
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A 30 kg child would weigh just under 5 kg on the Moon, explaining why Apollo astronauts could jump so high despite their bulky spacesuits.
No. Mass is the measure of the amount of matter in your body and is constant throughout the universe. Only weight — the gravitational force acting on your mass — changes depending on the local gravitational acceleration.
Surface gravity also depends on the radius. Jupiter's radius is about 11 times Earth's. The formula g = GM/r² means the huge radius partially offsets the enormous mass, resulting in a surface gravity of about 2.53g rather than the hundreds of g you might expect from mass alone.
No — Jupiter has no solid surface. The atmosphere transitions gradually into a metallic hydrogen interior. Even if there were a surface, the 2.53g gravity, extreme pressure, radiation belts, and temperature would be instantly lethal.
Venus is sometimes called Earth's twin because it has a similar mass (81.5% of Earth) and radius (95% of Earth). This results in a surface gravity of 8.87 m/s², about 90% of Earth's — very similar despite the hellish surface conditions.
The ISS orbits at about 400 km altitude where Earth's gravity is still about 88% as strong as on the surface (roughly 8.7 m/s²). Astronauts feel weightless not because there is no gravity but because they are in continuous free fall around Earth — a state called microgravity.
Surface gravity is g = GM/r², where G = 6.674x10-11 N m² kg-2 is the gravitational constant, M is the planet's mass in kilograms, and r is the planet's radius in meters. This formula follows directly from Newton's law of universal gravitation.
The Sun's surface gravity is about 274 m/s², roughly 28 times Earth's. A 70 kg person would effectively weigh about 1,957 kg on the Sun's surface — if the 5,500 degrees Celsius temperature and extreme radiation were somehow not a factor.
Among the major and dwarf planets, Pluto has very low surface gravity at 0.62 m/s² (about 6.3% of Earth's). Some smaller moons and asteroids have even weaker gravity — on asteroid Bennu, for example, you could escape the surface with a brisk walk.
In lower gravity, you can jump higher and run faster with less muscular effort. On the Moon (1/6g), the world record high jump of 2.45 m on Earth would translate to about 14.7 m. On Mars (3/8g), the same athlete could jump roughly 6.5 m high.
The calculator uses kilograms as a convenient unit of force for everyday use (technically kg-force, where 1 kg-force = 9.807 Newtons). For strictly scientific use, weight should be expressed in Newtons. To convert: multiply kg by the local g value to get Newtons.
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The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
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