Mass and weight are not the same thing
A bathroom scale does not measure how much "stuff" you are made of. It measures how hard your body presses down on it. The amount of matter in your body is your mass, and it is the same everywhere in the universe. Weight is a force: your mass multiplied by the local gravitational acceleration, W = m × g. Standard gravity on Earth is 9.80665 m/s², while the Moon's surface gravity is about 1.62 m/s². A person with a mass of 60 kg still has a mass of 60 kg on the Moon, but an Earth scale taken there would read about 9.9 kg. This calculator treats the number you enter as your mass, multiplies it by each world's gravity relative to Earth, and shows what an Earth-calibrated scale would display. It is handy for classroom demonstrations, science curiosity, and rough numbers for fiction or games.
The formulas
weight on another world (kg on an Earth scale) = Earth weight × (surface gravity ÷ 9.80665)actual force (N) = mass (kg) × surface gravity (m/s²)
Surface gravity follows g = G·M/r². It grows with the body's mass M and falls with the square of its radius r, which is why a very large planet does not necessarily pull as hard as its size suggests. The values in this tool are approximate figures consistent with NASA's planetary fact sheets, rounded to two decimals. Depending on the source, the latitude, and the altitude used, you will see slightly different numbers quoted elsewhere.
Surface gravity comparison
| Body | Surface gravity (m/s², approx.) | Relative to Earth | If you weigh 60 kg | If you weigh 70 kg | Height of an Earth 50 cm jump |
|---|---|---|---|---|---|
| βΏοΈ Mercury | 3.70 | 0.377x | 22.6 kg | 26.4 kg | about 1.33 m |
| βοΈ Venus | 8.87 | 0.904x | 54.3 kg | 63.3 kg | about 0.55 m |
| π Moon | 1.62 | 0.165x | 9.9 kg | 11.6 kg | about 3.03 m |
| βοΈ Mars | 3.73 | 0.380x | 22.8 kg | 26.6 kg | about 1.31 m |
| πͺ Jupiter | 25.92 | 2.643x | 158.6 kg | 185.0 kg | about 0.19 m |
| πͺ Saturn | 11.19 | 1.141x | 68.5 kg | 79.9 kg | about 0.44 m |
| π΅ Uranus | 9.01 | 0.919x | 55.1 kg | 64.3 kg | about 0.54 m |
| π· Neptune | 11.27 | 1.149x | 69.0 kg | 80.4 kg | about 0.44 m |
| βͺ Pluto | 0.62 | 0.063x | 3.8 kg | 4.4 kg | about 7.91 m |
The last column assumes you leave the ground at the same speed everywhere, in which case jump height is inversely proportional to gravity. By that simple model the Moon would give you roughly three times your Earth jump and Pluto about eight times. In reality a bulky pressurized suit and the extra mass it adds mean nobody jumps that high.
Worked examples (checked by direct calculation)
Example 1: a 60 kg adult on the Moon. 60 × 1.62 ÷ 9.80665 = 9.9 kg on an Earth scale. As a force that is 60 × 1.62 = 97.2 N, compared with 60 × 9.80665, about 588 N, on Earth. In other words, roughly one sixth.
Example 2: a 70 kg adult at Jupiter's 1 bar level. 70 × 25.92 ÷ 9.80665 is about 185.0 kg. That is 2.64 times your Earth weight pressing down on you, a load heavy enough to make breathing and circulation a serious problem, quite apart from the lack of anything to stand on.
Example 3: Mars and Mercury. Their surface gravities, 3.73 and 3.70 m/s², are nearly the same, so a 60 kg person would read about 22.8 kg on Mars and 22.6 kg on Mercury. Two very different worlds end up with similar gravity because mass and radius combine in different ways.
Common misunderstandings and limits
- You do not lose fat or muscle. Reading lighter on the Moon changes nothing about your mass, body composition or health.
- There is no ground on the giant planets. The values for Jupiter, Saturn, Uranus and Neptune refer to the altitude where the atmospheric pressure equals 1 bar, roughly sea-level pressure on Earth. They are a convention, not a place anyone could stand.
- Venus has Earth-like gravity but a hostile surface. Its surface pressure is very high and its temperature is hot enough to melt lead, so matching gravity says nothing about safety.
- Rotation changes the picture slightly. At a planet's equator the spin reduces the effective gravity compared with the poles; on Earth the difference is only about half a percent. This tool ignores it.
- Sources differ for the giants. NASA's fact sheet lists both a mean value and an equatorial value at the 1 bar level (for example 25.92 versus 23.12 m/s² for Jupiter, 11.19 versus 8.96 for Saturn, 9.01 versus 8.69 for Uranus, 11.27 versus 11.00 for Neptune). This page uses the mean values, so you may see a different multiple elsewhere, such as 2.36 for Jupiter's equatorial figure.
How to use the results
In a science class this makes a memorable way to separate mass from weight: have students enter their own numbers, compare the Moon with Jupiter, and then discuss why gravity depends on both mass and radius. For fiction and game design, the table helps you estimate fall times, jump heights and carrying loads for a given world. If you need figures for a publication, a lesson plan or a mission description, check the originating agency's published values directly and cite them.
Frequently Asked Questions
Jupiter is so much bigger than Earth, so why is its gravity only about 2.6 times as strong?
Surface gravity depends on mass and on the square of the radius. Jupiter's mass is more than 300 times Earth's, but its radius is about 11 times larger, so the pull at the 1 bar level grows far less than the mass ratio alone suggests.
Are Venus and Uranus really about the same in surface gravity?
They are close but not identical. Venus is about 8.87 m/s² (roughly 0.90 of Earth) and Uranus is about 9.01 m/s² at the 1 bar level (roughly 0.92). Uranus has no solid surface, so the 1 bar level is used as the reference.
Can I find out what I would weigh on the Sun?
This tool leaves it out. The Sun is a ball of gas without a clear surface, and although its surface gravity is often quoted as roughly 28 times Earth's, that figure is not a practical one to work with.
Is the number I type in treated as mass or weight?
The reading from your Earth scale is treated as your mass. The kilogram figures show what an Earth-calibrated scale would read on each world, and the newton figures show the real force.
Pluto is not a planet, so why is it listed?
The International Astronomical Union reclassified Pluto as a dwarf planet in 2006. It is still a common point of comparison, so it stays in the table and is labeled as a dwarf planet.