Planetary Weight Calculator
Accurately calculate weight on another planet and understand the physics of gravity.
Enter your current weight.
Please enter a valid positive number.
Pounds (lbs)
Kilograms (kg)
Newtons (N)
Stone (st)
Select the unit used for the input above.
Mercury (0.38g)
Venus (0.91g)
Earth (1.00g)
The Moon (0.166g)
Mars (0.38g)
Jupiter (2.34g)
Saturn (1.06g)
Uranus (0.92g)
Neptune (1.19g)
Pluto (0.06g)
The Sun (27.07g)
Choose which planet or body to travel to.
Weight on Mars
57.0 lbs
Weight Difference
-93.0 lbs
Gravity Ratio
38%
Mass (Invariant)
68.04 kg
The Math: Weight = 150 × 0.38 = 57.0. Since Mars has weaker gravity than Earth, you weigh less, though your physical mass remains exactly the same.
Gravity Comparison Chart
Full Solar System Breakdown
| Celestial Body | Relative Gravity | Your Weight | Difference |
|---|
*Values based on standard surface gravity relative to Earth (9.81 m/s²).
What is Calculate Weight on Another Planet?
When you calculate weight on another planet, you are determining the force exerted on your body by that planet's gravitational field. A common misconception is that "weight" and "mass" are the same thing. In reality, mass is the amount of matter in your body (measured in kilograms or slugs), while weight is a force (measured in Newtons or pounds) resulting from gravity acting on that mass.
This calculator is essential for students, physics enthusiasts, and science fiction writers who need to understand how different gravitational environments affect physical objects. Whether you are curious about how light you would feel on the Moon or how crushing the gravity of Jupiter would be, understanding how to calculate weight on another planet provides a fascinating perspective on our solar system.
Calculate Weight on Another Planet: Formula and Math
To understand the mechanics behind the tool, we must look at the fundamental physics equation for weight. The formula to calculate weight on another planet is derived from Newton's Law of Universal Gravitation.
The Core Formula:
W_planet = m × g_planet
However, since we usually start with your weight on Earth, it is easier to use the relative surface gravity method:
W_planet = W_earth × (g_planet / g_earth)
| Variable | Meaning | Standard Unit | Typical Range |
|---|---|---|---|
| W_planet | Target Weight | Newtons (N), lbs, kg* | 0 to Infinity |
| W_earth | Initial Weight on Earth | Newtons (N), lbs, kg* | User Input |
| g_planet | Planet's Gravity | m/s² | 0.58 (Pluto) to 274 (Sun) |
| g_earth | Earth's Gravity | m/s² | Constant: ~9.81 |
*Note: While kg is technically a unit of mass, in common parlance it is often used to denote weight (force) in Earth-gravity contexts.
Practical Examples (Real-World Use Cases)
Example 1: An Astronaut on the Moon
Imagine an astronaut weighing 180 lbs on Earth preparing for a lunar mission. The Moon's gravity is approximately 16.6% of Earth's.
- Input: 180 lbs
- Target: The Moon (0.166g)
- Calculation: 180 × 0.166
- Result: 29.88 lbs
Interpretation: The astronaut would feel significantly lighter, allowing for the characteristic "bouncing" gait seen in Apollo footage. This reduction in weight does not change the astronaut's inertia, meaning stopping or turning still requires the same effort as on Earth.
Example 2: A Rover on Jupiter
A scientific rover weighs 500 kg on Earth. Engineers need to know the structural load if it were to (hypothetically) land on Jupiter's "surface". Jupiter's gravity is roughly 2.34 times that of Earth.
- Input: 500 kg
- Target: Jupiter (2.34g)
- Calculation: 500 × 2.34
- Result: 1,170 kg
Interpretation: The rover's suspension system must be built to withstand over a tonne of force, more than double its Earth-rated capacity. Failure to calculate weight on another planet accurately in this scenario would lead to immediate structural collapse.
How to Use This Calculator
- Enter Your Weight: Input your current weight in the "Your Weight on Earth" field.
- Select Unit: Choose whether you are using pounds, kilograms, stone, or Newtons. This adjusts the labels but the ratio logic remains the same.
- Choose a Planet: Select a target celestial body from the dropdown menu (e.g., Mars, Venus, Titan).
- Analyze Results: The tool will instantly calculate weight on another planet.
- Primary Result: Your new weight on the target body.
- Mass (Invariant): Your mass in kilograms, which never changes regardless of location.
- Difference: How much weight you "lost" or "gained".
Key Factors That Affect Planetary Weight Results
When you calculate weight on another planet, several astrophysical factors influence the final number. Understanding these helps in grasping why gravity differs so wildly across the solar system.
- Planetary Mass: The more massive a planet, the stronger its gravitational pull. Jupiter is massive, hence high gravity.
- Planet Radius: Gravity weakens with distance from the center of mass. A large, fluffy planet (low density) might have lower surface gravity than a small, dense one.
- Density: Density plays a crucial role. Saturn is massive but very large and less dense than water, resulting in surface gravity barely higher than Earth's.
- Centrifugal Force: Planets spinning rapidly (like Saturn) reduce effective weight at the equator due to outward centrifugal force.
- Altitude: The "surface" is defined differently for gas giants. Weight would change drastically depending on how deep into the atmosphere you measure.
- Local Geology: On smaller bodies like the Moon or Mars, local concentrations of mass (mascons) can cause slight variations in gravity measurements.
Frequently Asked Questions (FAQ)
Does my mass change when I go to another planet?
No. Mass is the measure of how much matter constitutes your body. If you are 70kg on Earth, you are 70kg on the Moon. Only your weight (the force of gravity pulling on that mass) changes when you calculate weight on another planet.
Which planet has gravity most similar to Earth?
Saturn (1.06g), Venus (0.91g), and Uranus (0.92g) are the closest. Venus is often considered Earth's "sister planet" due to similar size and gravity, though its atmosphere is crushing.
Why is Pluto's gravity so low?
Pluto is extremely small and has low density. Its gravity is only about 6% of Earth's. A 150lb person would weigh roughly 9lbs on Pluto.
How is weight calculated for gas giants like Jupiter?
Since gas giants have no solid surface, the "surface" gravity is typically defined at the altitude where atmospheric pressure equals 1 bar (Earth's sea level pressure).
Can I use this to calculate weight on the Sun?
Yes, our tool includes the Sun. However, standing on the Sun is impossible. The gravity is about 27 times stronger than Earth, meaning a human would be crushed instantly by their own weight.
Is gravity the same everywhere on Earth?
Not exactly. Gravity is slightly stronger at the poles and weaker at the equator due to Earth's rotation and slightly oblate shape, but for general purposes, we use the average standard of 9.81 m/s².
What unit should I use for scientific calculations?
For physics and astrophysics, Newtons (N) is the standard unit for weight (force), and kilograms (kg) is the standard for mass.
How accurate are these planetary constants?
They are approximations based on NASA planetary fact sheets. Values can vary slightly depending on the specific definition of the planet's radius and rotational speed.
Related Tools and Internal Resources
Explore more of our astronomical and physics-based calculators:
- Planetary Gravity Calculator – Compare G-forces across the solar system.
- Mass vs. Weight Explainer – Deep dive into the definitions.
- Weight on Mars Calculator – Dedicated tool for Mars colonization planning.
- Weight on Moon Simulator – See how high you could jump on the Moon.
- Newton's Laws of Motion – The fundamental physics behind the calculations.
- Escape Velocity Calculator – Calculate speed needed to leave a planet.