Weight on Other Planets Calculator

Your mass does not change when you leave Earth. Your weight changes enormously — by a factor of 33 between Pluto and Jupiter. Enter your mass once and read your weight on ten worlds, with the surface gravity and radius taken from NASA’s Planetary Fact Sheet, and a height box so you can watch the weight fall as you climb away.

Last updated 11 Nov 2026

Your weight on ten worlds, at the surface or above it

W = mg, with a different g everywhere

Your mass (kg)A bathroom scale on Earth gives you this directly, which is lucky, because what the scale really measures is a force — it divides by Earth’s g before printing a number for you. Take the same scale to the Moon and it would under-read by a factor of six.

Which worldMercury and Mars both have a surface gravity of 3.7 m/s² to the precision NASA publishes, despite Mars being nearly three times Mercury’s mass — Mars is also much bigger, and surface gravity depends on mass divided by radius squared, so the two effects very nearly cancel. Pluto is included because it is interesting, not as a claim about what counts as a planet.

Height above the surface (km)Leave at 0 for surface gravity. Put in 400 km — the altitude of the International Space Station — and Earth’s g drops to about 8.7 m/s², which is 89% of its surface value, not zero. Astronauts float because they are falling, not because gravity has gone.

Which Earth g to compare againstThe ratios on this page are against this figure. The fact sheet’s own Earth row says 9.8, so that is the default and it keeps every bar in the chart on one source. Standard gravity is exactly 9.806 65 m/s² — a conventional value adopted by the 3rd CGPM in 1901, not a measurement of any particular place; real surface gravity on Earth varies from about 9.78 at the equator to 9.83 at the poles.

Your weight on ten worlds, to one scale. Left to right: Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. Your chosen world is the red bar with the pointer above it; the red dashed line carries its height across the others so you can read the comparison off directly, and the grey dashed line is Earth's surface gravity. Raise the height box and every bar shrinks — the small worlds fastest, because they have the smallest radii.

222.00NExample

A student with a mass of 60 kg stands on the surface of Mars. Mars has a surface gravity of 3.7 m/s². Find the student’s weight there, and compare it with their weight on Earth taken at 9.8 m/s².

One formula, one changing letter

W = mg · g = g₀ (R / (R + z))² · 1 N = 1 kg·m/s²

m: mass in kilograms. The same number everywhere in the universe.
g: gravitational field strength in m/s², or equivalently N/kg — the two units are identical and the second says what g means more plainly: newtons of pull per kilogram of you.
g₀: surface gravity of the world, from the NASA fact sheet.
R: the world’s radius, taken as half the published diameter.
z: height above the surface. It is added to R because gravity depends on the distance from the centre.

Worked example

A student with a mass of 60 kg stands on the surface of Mars. Mars has a surface gravity of 3.7 m/s². Find the student's weight there, and compare it with their weight on Earth taken at 9.8 m/s².
Weight on Mars. W = mg = 60 × 3.7 = 222 N. The mass went into the formula in kilograms and came out multiplied by an acceleration, so the answer is in newtons. Writing “222 kg” here is the single commonest error on this topic and it is worth half the marks.
Weight on Earth for comparison. W = 60 × 9.8 = 588 N. The student's mass is 60 kg in both calculations — nothing about the person changed, only the field they are standing in.
The ratio. 222 ÷ 588 = 0.378, or equivalently 3.7 ÷ 9.8 = 0.378. The mass cancels, which is why the bar chart has the same shape for everybody: the ratio between two worlds does not depend on who is standing there.
What a bathroom scale would say. A scale calibrated on Earth divides the force it feels by 9.8 before printing. On Mars it feels 222 N, so it prints 222 ÷ 9.8 = 22.7 kg. The student has not lost 37 kg; the scale is simply the wrong instrument for the job.
Now climb. Mars's radius is 3396 km. At 500 km up, g = 3.7 × (3396/3896)² = 3.7 × 0.7597 = 2.81 m/s², and the weight falls to 169 N — a 24% drop for a height of only 15% of the radius, because the relationship is an inverse square.
One sanity check that costs nothing. Divide your answer in newtons by 10. That is roughly the weight in kilogram-force, and on Earth it should come out close to your mass in kilograms. If it does not, you have mixed up a mass and a weight somewhere.

A 60 kg person across the Solar System, from the NASA Planetary Fact Sheet

Every figure in the first two columns is read straight off NASA’s Planetary Fact Sheet (Metric); the radii are half the published diameters. Mercury and Mars tie at 3.7 m/s² even though Mars is nearly three times as massive, because surface gravity goes as mass divided by radius squared and Mars is also the larger world. Jupiter’s and Saturn’s figures are at the one-bar level of their atmospheres, since neither has a surface to stand on. The last column is what a scale from your bathroom would display, and the gap between it and 60 kg is the whole point of the page.
World	Surface gravity (m/s²)	Radius (km)	Weight of a 60 kg person (N)	× Earth	Earth-calibrated scale reads (kg)
Mercury	3.7	2439.5	222	0.378	22.7
Venus	8.9	6052.0	534	0.908	54.5
Earth	9.8	6378.0	588	1.000	60.0
Moon	1.6	1737.5	96	0.163	9.8
Mars	3.7	3396.0	222	0.378	22.7
Jupiter	23.1	71492.0	1386	2.357	141.4
Saturn	9.0	60268.0	540	0.918	55.1
Uranus	8.7	25559.0	522	0.888	53.3
Neptune	11.0	24764.0	660	1.122	67.3
Pluto	0.7	1188.0	42	0.071	4.3

Mass or weight? The quantities that get confused

The 3rd CGPM settled this in 1901, in a declaration written specifically to end the confusion: the kilogram is a unit of mass, and “weight” denotes a quantity of the same nature as a force, equal to the mass times the acceleration due to gravity. Everyday English has never caught up — we all say we weigh 60 kilograms — and the exam mark scheme has. If the question asks for a weight and your answer has kg after it, something is wrong.
Quantity	Symbol	SI unit	Changes with location?	Measured by
Mass	m	kilogram (kg)	No	A balance, comparing with known masses
Weight	W	newton (N)	Yes	A spring balance or force meter
Gravitational field strength	g	N/kg, identical to m/s²	Yes	Timing a fall, or a pendulum
Kilogram-force	kgf	Not SI; 1 kgf = 9.806 65 N exactly	It is a force, so the unit is fixed	Historical; the value the 3rd CGPM fixed in 1901
“Weight” on a bathroom scale	—	Printed in kg, but it senses newtons	Yes, and silently	A spring or load cell, divided by Earth’s g

Why your mass travels with you and your weight does not

Mass and weight are different quantities with different units, and everything on this page follows from that. Mass is a property of you: how much matter you are made of, and equally how hard you are to accelerate. Take it to Mars, to the bottom of the ocean or into deep space and it is unchanged. Weight is not a property of you at all — it is the size of the gravitational force acting on you, and it needs two things to exist: your mass, and a world to pull on it. Remove the world and the weight goes; the mass stays.

The formula is W = mg, where g is the gravitational field strength. It is worth getting comfortable with g written in newtons per kilogram rather than metres per second squared, because the two units are identical and the first says what the quantity does: on Earth every kilogram of you is pulled with about 9.8 newtons. Sixty kilograms, 588 newtons. On the Moon, 1.6 newtons per kilogram, so 96 newtons. The pull per kilogram changes; the number of kilograms does not.

Why does surface gravity vary so much? Because it depends on both the world’s mass and its radius: g = GM/R², so a big heavy world can have modest surface gravity if it is also very large. Saturn is 95 times Earth’s mass and its surface gravity is 9.0 m/s², slightly less than Earth’s, because its radius is nearly ten times larger and the radius is squared in the denominator. Mercury and Mars make the same point from the other end: Mars has nearly three times Mercury’s mass and they tie at 3.7 m/s². If you want to know how hard a world pulls, its mass alone will not tell you. The gravitation page does that calculation from first principles.

The height box exists because of a very common misconception. Gravity does not stop at the top of the atmosphere. At the International Space Station’s 400 km altitude, Earth’s field is still about 8.7 N/kg — close to 89% of the surface value — and an astronaut there weighs almost as much as they do on the ground. They float because the station and everything in it are in continuous free fall around the Earth, which is a completely different statement from “there is no gravity”. To halve your weight you have to climb to about 2 640 km, and to get g down to a tenth you must be roughly two Earth radii out. Notice too that the small worlds lose their gravity fastest as you climb, because the height matters relative to the radius: 500 km above Pluto is a long way out, and 500 km above Jupiter is nothing at all.

Where this goes wrong is units, every time. The answer to “what is your weight on Mars” is 222 newtons, not 222 kilograms and not 22.7 kilograms. The 22.7 figure is real — it is what an Earth-calibrated bathroom scale would display — but it is a scale reading, not a weight, and the only reason it looks like a mass is that the scale quietly divided by Earth’s g on your behalf. A spring balance measures force honestly; a two-pan balance measures mass honestly, because it compares your unknown against known masses in the same field and the field cancels. A two-pan balance gives the same answer on the Moon. A bathroom scale does not.

A final thought experiment that ties the page together. Drop a hammer and a feather together on the Moon, as David Scott did on Apollo 15, and they land at the same instant. The hammer is pulled far harder — it has far more weight — but it also has far more mass to accelerate, and the two effects cancel exactly. That is why g is both a field strength in N/kg and an acceleration in m/s², and why the fall time in the figures above depends only on the world you are on and not at all on what you drop.

Frequently asked questions

Would I weigh less on the Moon or have less mass?

Less weight, the same mass. Your Moon weight is about 16% of your Earth weight because the Moon’s surface gravity is 1.6 m/s² against Earth’s 9.8. Your mass in kilograms is unchanged — you are made of exactly the same amount of stuff — and you would be exactly as hard to shove sideways, which is a thing the Apollo crews commented on.

Why do Mercury and Mars have the same surface gravity?

Coincidence, arising from g = GM/R². Mars is about 1.95 times Mercury’s mass, which on its own would make Mars pull harder; but Mars’s radius is about 1.39 times Mercury’s, and squaring that gives 1.94 in the denominator. The two factors cancel to within the precision NASA publishes, and both come out at 3.7 m/s².

Is there really gravity on the Space Station?

Yes, nearly as much as on the ground — about 8.7 N/kg at 400 km, which is 89% of the surface value. Astronauts appear weightless because the station is in free fall: it is falling towards Earth continuously and moving sideways fast enough to keep missing. Everything inside falls at the same rate, so nothing presses on anything, and that is what floating is. The correct phrase is “apparent weightlessness” or “microgravity”, not “zero gravity”.

What units should my answer be in?

Newtons, for a weight. If the question gives a mass in kilograms and a g in m/s², the product is automatically in newtons, because 1 N is defined as 1 kg·m/s². You may also meet the kilogram-force, where 1 kgf is exactly 9.806 65 N — that is the unit behind the everyday habit of quoting weight in kilograms, and it is not an SI unit.

Does Jupiter have a surface to stand on?

No. Jupiter and Saturn are gas giants with no solid surface, so the “surface gravity” in the table is the value at the level where the atmospheric pressure is one bar, which is the convention the fact sheet uses. The number is real and useful for comparison; the picture of standing on it is not.

Why does my weight fall so slowly as I climb a mountain?

Because the height is tiny compared with Earth’s radius. On top of Everest you are 8.8 km up out of 6 378 km, so g falls by about 0.28% — roughly 1.6 N off a 588 N weight, which no bathroom scale would show you. Gravity weakens with the square of the distance from the centre of the planet, not the distance from the ground, and that is the distinction the height box on this page is built around.

Related calculators

References

NASA, Planetary Fact Sheet — Metric, NASA Space Science Data Coordinated Archive, read 11 November 2026. The “Gravity (m/s²)” and “Diameter (km)” rows supply every surface gravity and radius on this page. nssdc.gsfc.nasa.gov/planetary/factsheet/
BIPM, Declaration on the unit of mass and on the definition of weight; conventional value of g_n — Declaration 2 of the 3rd CGPM (1901). Declares the kilogram the unit of mass, states that “weight” denotes a quantity of the same nature as a force, and adopts a standard acceleration of 980.665 cm/s². The official version is the French text.
NIST, CODATA Internationally Recommended 2022 Values of the Fundamental Physical Constants, ASCII table read 11 November 2026. Standard acceleration of gravity 9.806 65 m s⁻², marked (exact) rather than carrying an uncertainty; Newtonian constant of gravitation 6.674 30(15)×10⁻¹¹ m³ kg⁻¹ s⁻². physics.nist.gov/cuu/Constants/Table/allascii.txt
BIPM, The International System of Units (SI), 9th edition (2019, updated 2026). The newton, the pascal and the kilogram: the kilogram is a unit of mass and the newton a unit of force, and the brochure keeps them in separate tables for the reason this page keeps repeating.