What Would You Weigh on Mars?
Stepping onto Mars, you'd instantly feel lighter — not because you've changed, but because gravity has. This guide explains the difference between mass and weight, why Mars's gravity is ~38% of Earth's, and how to convert your Earth weight to a Martian one accurately. Use this to make sense of the number you'll see in our tool — and what it means for real life on the Red Planet.
Try it now: Space Weight Calculator • Also see: Age on Mars Calculator
Weight vs Mass (The One-Liner You'll Remember)
- Mass: how much "stuff" you're made of — it doesn't change with location
- Weight: gravitational force on that mass — it depends on the planet
On Earth, surface gravity is about 9.81 m/s². On Mars, it's 3.71 m/s² — roughly 0.38× Earth.
That ratio lets you convert instantly:
Weight on Mars = Weight on Earth × 0.38
If you prefer working from mass:
Weight (N) = Mass (kg) × g (m/s²)
- Earth:
W = m × 9.81 - Mars:
W = m × 3.71
Our calculator uses the above ratio for a quick, intuitive number.
Why Mars Pulls Less
Gravity at a planet's surface depends on mass and radius:
g = (G × M) / r^2
Where:
- G = gravitational constant
- M = planet's mass
- r = planet's radius
Mars has ~11% of Earth's mass and about 53% of Earth's radius. Smaller radius concentrates gravity, but the much lower mass dominates, yielding ~0.38 g_Earth
What Lower Gravity Does to You
- Motion: jumps feel springy; sprints have longer hang-time
- Bones/Muscles: long-term deconditioning without countermeasures (think ISS lessons)
- Posture: slight spinal decompression; you may stand a tad taller
- Daily life: loads, tools, and safety standards must be rethought
Across the Solar System (Perspective)
| World | Surface g (× Earth) | 70 kg on Earth → | |---|---:|---:| | Mercury | ~0.38 | ~26.6 kg (effective) | | Venus | ~0.91 | ~63.7 kg | | Mars | ~0.38 | ~26.6 kg | | Jupiter | ~2.53 | ~177 kg | | Saturn | ~1.06 | ~74 kg | | Uranus | ~0.89 | ~62 kg | | Neptune | ~1.14 | ~80 kg |
Worked Examples
Example 1 — Quick Ratio
Ayo is 80 kg on Earth. On Mars:
80 × 0.38 = 30.4 kg (effective weight equivalent)
Example 2 — From Mass & g
Mass m = 65 kg.
- Earth weight (N):
65 × 9.81 ≈ 637 N - Mars weight (N):
65 × 3.71 ≈ 241 NRatio:241 / 637 ≈ 0.378→ ~38%
Try it yourself in the calculator above and compare with Jupiter or the Moon for fun.
Frequently Asked Questions
Is the calculator showing "mass" or "weight"?
We present an Earth-scale equivalent (what a bathroom scale would read if it were calibrated like Earth's). If you need force in newtons, use the mass×g method described above.
Why do some tables show slightly different numbers?
Different sources round gravity values differently. We use widely accepted standard values and clearly state assumptions.
Does clothing or gear change the reading?
Yes — anything you carry adds to mass, which scales the weight number on any world.
Related Articles:
- Space Weight Calculator - Compare your weight across all planets
- Age on Mars Calculator - Calculate your exact age on the Red Planet
- Planetary Years Explained - Understand orbital periods across planets
- Time on Mars Explained - Learn about Martian sols and seasons