Moon Weight Calculator
Accurately calculate the weight of a person standing on the moon using current astrophysical constants.
Enter your current weight.
Please enter a valid positive number.
Pounds (lbs)
Kilograms (kg)
Stone (st)
Select the unit for the calculation.
Your Weight on the Moon
24.8 lbs
Formula Used: Weight (Moon) = Weight (Earth) × (1.62 m/s² / 9.81 m/s²). The moon's gravity is approximately 16.5% of Earth's gravity.
Calculated Mass
68.0 kg
Weight on Mars
56.8 lbs
Weight on Jupiter
379.2 lbs
Percentage of Earth Weight
16.54%
Planetary Weight Comparison
Detailed Gravitational Breakdown
| Celestial Body | Relative Gravity (g) | Your Weight | Difference from Earth |
|---|
What is the Calculation of Weight on the Moon?
To calculate the weight of a person standing on the moon is to determine the force exerted on that person's mass by the moon's gravitational field. Unlike mass, which remains constant regardless of your location in the universe, weight is a variable force that changes based on the gravitational acceleration of the planet or moon you are standing on.
This calculation is essential for astrophysicists planning lunar missions, engineers designing spacesuits (extravehicular mobility units), and STEM students learning the fundamental difference between mass and weight. While Earth has a substantial gravitational pull due to its density and size, the moon is much smaller and less dense, resulting in a significantly weaker gravitational force.
A common misconception is that a person has "no weight" on the moon. This is incorrect. While the weight is drastically reduced, the moon does have gravity, and astronauts must still exert effort to move, albeit differently than on Earth.
Moon Weight Formula and Mathematical Explanation
To accurately calculate the weight of a person standing on the moon, we use Newton's Law of Universal Gravitation concepts derived into a comparative ratio. The formula compares the gravitational acceleration of the Moon to that of the Earth.
The Core Formula
Wmoon = Wearth × (gmoon / gearth)
Where:
- Wmoon: The resulting weight on the Moon.
- Wearth: The input weight on Earth.
- gmoon: Acceleration due to gravity on the Moon (~1.622 m/s²).
- gearth: Acceleration due to gravity on Earth (~9.807 m/s²).
The ratio of lunar gravity to Earth gravity is roughly 0.1654, or 16.54%. This means you can simply multiply your Earth weight by 0.1654 to get a very close approximation.
Variables Table
| Variable | Meaning | Standard Unit | Typical Value |
|---|---|---|---|
| W | Weight (Force) | Newtons (N) or lbs | Variable |
| m | Mass | Kilograms (kg) | Constant |
| g | Gravitational Acceleration | m/s² | 9.807 (Earth) |
Practical Examples (Real-World Use Cases)
Example 1: The Average Astronaut
Consider an astronaut who weighs 180 lbs on Earth. To calculate the weight of a person standing on the moon for this astronaut:
- Input: 180 lbs
- Calculation: 180 × 0.1654
- Result: 29.77 lbs
Financial/Logistical Interpretation: In terms of mission planning, this low weight allows astronauts to carry life-support systems that weigh nearly 300 lbs on Earth because they would only feel like ~50 lbs on the Moon.
Example 2: Equipment Payload in Metric
A rover weighing 500 kg (mass-weight equivalent on Earth) is sent to the moon.
- Input: 500 kg
- Calculation: 500 × 0.1654
- Result: 82.7 kg
Interpretation: The suspension system of the rover needs to be designed not for 500kg of force, but for the reduced lunar weight, while still managing the momentum of the full 500kg mass.
How to Use This Moon Weight Calculator
This tool is designed for simplicity and accuracy. Follow these steps to calculate the weight of a person standing on the moon:
- Enter Earth Weight: Input your current weight in the "Your Weight on Earth" field. Ensure the value is positive.
- Select Unit: Choose between Pounds (lbs), Kilograms (kg), or Stone (st) from the dropdown menu. The calculator automatically handles the conversions.
- Review Results: The primary result box will immediately show your lunar weight.
- Analyze Comparisons: Look at the "Intermediate Values" and the "Planetary Weight Comparison" chart to see how your weight would differ on Mars or Jupiter.
- Copy Data: Use the "Copy Results" button to save the data for your reports or homework.
Key Factors That Affect Moon Weight Results
While the standard gravity ratio is 0.1654, several nuanced factors can affect the precise calculation when you calculate the weight of a person standing on the moon.
- Lunar Gravity Anomalies (Mascons): The moon does not have a perfectly uniform density. Concentrations of mass (mascons) beneath impact basins can locally increase gravitational pull slightly.
- Altitude/Elevation: Just like on Earth, gravity is weaker at higher altitudes (tops of lunar mountains) and stronger in lowlands, though the difference is minute for human scales.
- Mass vs. Weight Distinction: Users often confuse mass with weight. If you gain muscle mass, your weight increases on both Earth and the Moon proportionally.
- Gear and Equipment: In a practical scenario, you never stand on the moon "naked." An Apollo-era spacesuit weighs roughly 180 lbs on Earth. This must be added to your body weight before applying the ratio.
- Centrifugal Force: The moon rotates very slowly (once every 27 days). Unlike Earth, where centrifugal force at the equator reduces weight slightly, the moon's slow rotation makes this factor negligible.
- Tidal Forces: The Earth exerts a tidal force on the Moon. While this affects the lunar surface shape, its direct impact on a standing human's weight measurement is infinitesimally small but physically present.
Frequently Asked Questions (FAQ)
Q: Does my mass change when I go to the moon?
A: No. Mass is the amount of matter in your body and remains constant anywhere in the universe. Only your weight (the force of gravity on that mass) changes.
A: No. Mass is the amount of matter in your body and remains constant anywhere in the universe. Only your weight (the force of gravity on that mass) changes.
Q: Why is the gravity on the moon so much lower?
A: The moon has only about 1.2% of Earth's mass and is about 27% the size of Earth. Less mass means less gravitational pull.
A: The moon has only about 1.2% of Earth's mass and is about 27% the size of Earth. Less mass means less gravitational pull.
Q: Can I jump 6 times higher on the moon?
A: Theoretically, yes, because you are fighting less gravity. However, spacesuits are bulky and restrict movement, which usually limits jump height in practice.
A: Theoretically, yes, because you are fighting less gravity. However, spacesuits are bulky and restrict movement, which usually limits jump height in practice.
Q: Is the conversion factor exactly 16.5%?
A: It is approximately 16.54%. The calculator uses the precise ratio of 1.622/9.807 for maximum accuracy.
A: It is approximately 16.54%. The calculator uses the precise ratio of 1.622/9.807 for maximum accuracy.
Q: How does this help with financial planning for space travel?
A: Weight equals cost. Every pound of payload costs thousands of dollars to launch. Knowing exact weights allows for precise fuel budgeting and cost estimation.
A: Weight equals cost. Every pound of payload costs thousands of dollars to launch. Knowing exact weights allows for precise fuel budgeting and cost estimation.
Q: What would a 100kg person weigh on the moon?
A: A 100kg person (mass) would weigh approximately 16.5kg-force on the moon.
A: A 100kg person (mass) would weigh approximately 16.5kg-force on the moon.
Q: How do I calculate weight on Mars?
A: Mars gravity is 3.721 m/s². Multiply your Earth weight by roughly 0.38. Our tool automatically displays this comparison.
A: Mars gravity is 3.721 m/s². Multiply your Earth weight by roughly 0.38. Our tool automatically displays this comparison.
Q: Does the "Stone" unit work on the moon?
A: Yes, "Stone" is just a unit of mass/weight used in the UK/Ireland. The physics ratio applies regardless of the unit used.
A: Yes, "Stone" is just a unit of mass/weight used in the UK/Ireland. The physics ratio applies regardless of the unit used.
Related Tools and Internal Resources
Expand your knowledge of astrophysical calculations with our suite of tools designed to help you calculate the weight of a person standing on the moon and beyond.
- Planetary Gravity Calculator – Compare your weight across all 8 planets and Pluto.
- Mass vs. Weight Physics Guide – A deep dive into the fundamental differences between matter and force.
- Escape Velocity Tool – Calculate the speed needed to break free from Moon or Mars gravity.
- Rocket Payload Cost Estimator – Financial tool for estimating launch costs based on weight.
- Space Mission Planning Checklist – Logistics and weight considerations for lunar exploration.
- Astrophysics Formulas Sheet – Downloadable reference for gravity, orbit, and weight equations.