How strong is gravity on Mars? About 38% of Earth’s gravity

Gravity on Mars is about 3.7 metres per second squared (m/s²), or 38% of Earth’s 9.8 m/s², so gravity is weaker on Mars than on Earth, not stronger. Something that reads 100 lb on a bathroom scale on Earth would read about 38 lb on the same scale on Mars.

The object’s mass would not change at all. Only its weight, the force of gravity acting on that mass, would drop to a little more than a third of its Earth value.

Key facts about gravity on Mars

• Mean surface gravity: 3.73 m/s², according to NASA’s Mars fact sheet.
• Compared with Earth: 0.38 times Earth’s gravity, often written 0.38 g.
• Why it is lower: Mars has 10.7% of Earth’s mass and 53% of its radius.
• Escape velocity: 5.03 km/s, compared with 11.19 km/s for Earth.
• Near twin: Mercury’s surface gravity, 3.70 m/s², is almost identical, even though Mars has about twice Mercury’s mass.

Is gravity stronger on Mars than on Earth?

No. Mars’s gravity is about 62% weaker than Earth’s. Every object on Mars is pulled toward the ground with about 0.38 times the force it would feel on Earth.

Mars still has plenty of gravity. It holds a thin atmosphere, keeps two small moons, Phobos and Deimos, in orbit, and pulls dust, rocks and landing spacecraft firmly to its surface. “Low” gravity here means low compared with Earth, not absent.

Why do sources say 3.71, 3.72 or 3.73 m/s²?

All three figures are reasonable. They differ because they measure gravity in slightly different places or ways:

Sources: NASA NSSDCA Mars and Earth fact sheets (mean, equatorial with rotation and polar rows); NASA JPL Solar System Dynamics, Planetary Physical Parameters (equatorial gravity without rotation). Ratios calculated by SciQuest.

The ratio barely moves: Mars’s gravity is 38% of Earth’s by any of these definitions. Mars spins once every 24.6 hours, about as fast as Earth, so rotation trims only about 0.02 m/s² at its equator.

How is gravity on Mars calculated?

For a round planet, surface gravity follows from Newton’s law of gravitation:

g = GM/R²

Here G is the gravitational constant, M is the planet’s mass and R is its radius. Using NASA’s values for Mars:

• G = 6.674 × 10⁻¹¹ m³ kg⁻¹ s⁻²
• M = 6.4169 × 10²³ kg, so GM ≈ 4.283 × 10¹³ m³/s²
• R = 3,389.5 km = 3.3895 × 10⁶ m, so R² ≈ 1.1489 × 10¹³ m²
• g = 4.283 × 10¹³ ÷ 1.1489 × 10¹³ ≈ 3.73 m/s²

The same answer comes from comparing Mars directly with Earth. Mars has 0.1074 of Earth’s mass and 0.5320 of its radius. Gravity scales with mass divided by radius squared:

0.1074 ÷ (0.5320)² = 0.1074 ÷ 0.2830 ≈ 0.380
0.380 × 9.82 m/s² ≈ 3.73 m/s²

Note that the ratio shortcut only works when it is multiplied by Earth’s gravity calculated the same way. That is why this page uses Earth’s mean value of 9.82 m/s² here, not the conventional “standard gravity” of 9.80665 m/s².

Why is Mars’s gravity so much weaker than Earth’s?

Mars is small and less dense. Its mean density is 3,934 kg/m³, compared with 5,513 kg/m³ for Earth, so each cubic metre of Mars holds about 29% less mass on average. NASA’s fact sheet gives Mars about 15% of Earth’s volume but only 10.7% of its mass.

The smaller radius partly compensates. On Mars you stand about half as far from the centre of the planet, and gravity strengthens with the inverse square of that distance. If Mars had Earth’s radius but kept its own mass, its surface gravity would be only about 11% of Earth’s, not 38%.

Mercury shows how the two effects can cancel out. Mars has 1.94 times Mercury’s mass, but its radius is 1.39 times larger, and 1.39² ≈ 1.93. The result is nearly identical surface gravity: 3.73 m/s² on Mars and 3.70 m/s² on Mercury.

How much would you weigh on Mars?

Weight is a force, measured in newtons (N):

Weight = mass × gravitational acceleration

Calculated by SciQuest using standard gravity (9.80665 m/s²) for Earth, NASA’s mean Mars value (3.73 m/s²) and the Mars-to-Earth mean ratio of 0.380 for scale readings.

A bathroom scale measures force and converts it into kilograms or pounds assuming Earth gravity. That is why it would show a smaller number on Mars, even though your body contains exactly the same amount of matter. Your mass still resists starting, stopping and turning just as it does on Earth, so a heavy load would feel light to lift but would be no easier to stop once it was moving.

How high could you jump on Mars?

With the same push-off speed, jump height is inversely proportional to gravity. In an idealised calculation, a jump would rise about 2.6 times as high on Mars as on Earth (9.81 ÷ 3.73 ≈ 2.63). A 50 cm standing jump on Earth would become about 1.3 m.

Falls would also be slower. Ignoring air resistance, an object dropped from 1 m takes 0.45 seconds to land on Earth, 0.73 seconds on Mars and 1.11 seconds on the Moon, using t = √(2h/g).

Real astronauts would not achieve the ideal figure. A pressurised spacesuit and life-support pack add mass and limit how joints bend, so practical jumps would be lower. SciQuest’s explainer on gravity on the Moon describes how Apollo astronauts adapted to an even lower 0.165 g.

Can humans walk normally in Mars gravity?

Yes, but walking would change. On Earth, we walk partly by falling forward and swinging back up like an inverted pendulum, which uses gravity to recycle energy. In a 1998 study in Nature, G. A. Cavagna, P. A. Willems and N. C. Heglund studied walking aboard an aircraft flying gravity-reducing flight profiles. They predicted that the optimal walking speed on Mars would be 3.4 km/h, down from 5.5 km/h on Earth.

The same study found that the work needed to move the body’s centre of mass over each metre would be about half the Earth value. Walking on Mars would therefore be slower at its most efficient pace but would need less mechanical work per metre travelled. That result comes from short periods of simulated gravity, not from people living on Mars.

Is Mars gravity enough to keep astronauts healthy?

Nobody knows yet. No human has spent time in Mars-level gravity, so its long-term effects on bones, muscles and other body systems have not been measured.

The closest evidence comes from weightlessness. NASA’s Human Research Program reports that weight-bearing bones lose on average 1% to 1.5% of their mineral density per month during spaceflight. NASA notes that a Mars crew would face three gravity environments: weightlessness during a roughly six-month transit, about one-third of Earth’s gravity on Mars, and readaptation to full gravity on return. Whether 0.38 g is enough to slow or prevent bone and muscle loss is an open research question. This section is educational and is not medical advice.

Is gravity the same everywhere on Mars?

No. The 3.73 m/s² figure is an average. Surface gravity changes slightly with altitude, because standing on a high volcano puts you farther from the planet’s centre, and with dense or light rock underground. Mars has a 30 km range between its highest and lowest points, according to NASA’s fact sheet, compared with 20 km on Earth.

In 2016, NASA released its most detailed Mars gravity map to that date, led by Antonio Genova, then at the Massachusetts Institute of Technology. The team built it from Deep Space Network Doppler and range tracking of three orbiters: Mars Global Surveyor, Mars Odyssey and Mars Reconnaissance Orbiter. Tiny changes in the spacecraft’s motion revealed variations in gravity. The data also confirmed that Mars has a liquid outer core and showed the planet’s gravity changing as 3 to 4 trillion tons of carbon dioxide froze onto a polar cap each winter.

How does Mars gravity compare with other worlds?

Source: NASA NSSDCA fact sheets for the Moon, Mercury, Mars, Venus and Earth. NASA’s Moon sheet gives a ratio of 0.165 against an Earth value of 9.80 m/s².

Mars needs less than half Earth’s launch speed to escape. A lower escape velocity makes it easier for gas molecules to leave a planet, which is one of several reasons Mars has a much thinner atmosphere than Earth. Temperature, the solar wind and the lack of a global magnetic field also matter. SciQuest’s article on what the Martian atmosphere is made of covers its composition and pressure.

For the giant planets, see SciQuest’s pages on gravity on Jupiter and gravity on Saturn. Every planet, plus major moons and Pluto, appears in one table in our guide to gravity on other planets.

What scientists do not know yet

The physics of Mars’s gravity is well measured: its value is known to three significant figures, and orbiters have mapped its variations in detail. The biology is not. How the human body adapts to months or years at 0.38 g, whether that level of gravity protects bone and muscle, and how quickly people readjust to Earth afterwards are questions that only long missions or long-duration partial-gravity experiments can answer.

Related reading

• How far is Mars from Earth? Closest, average and farthest distance
• Can humans survive on Mars?
• Gravity on other planets: every planet compared

Update note: This article was substantially revised on October 12, 2026. We corrected the worked calculation, which previously did not reproduce its own answer; replaced statements that confused mass with weight; corrected Earth’s gravity from 0.98 g to 1 g; reconciled the 3.71–3.73 m/s² values; replaced the comparison table, including a wrong value for Callisto; and resolved contradictory claims about walking speed using the original study. Content from the former page “Is gravity stronger on Mars?” has been merged here, and its unsupported claims about skin colour, eyesight and immunity were not carried over. It was drafted with AI assistance and checked against the sources listed below.

Sources

• NASA NSSDCA, Mars Fact Sheet
• NASA NSSDCA, Earth Fact Sheet
• NASA NSSDCA fact sheets: Mercury, Venus, Moon
• NASA JPL Solar System Dynamics, Planetary Physical Parameters
• Cavagna, G. A., Willems, P. A., and Heglund, N. C. (1998), Walking on Mars, Nature 393:636
• NASA Human Research Program, Hazard: Gravity Fields
• NASA JPL, New Gravity Map Gives Best View Yet Inside Mars (2016)