Easily calculate your weight on any celestial body by inputting your Earth weight and selecting a planet or moon. Understand how gravity affects your mass across the universe.
Gravity Weight Converter
Enter your weight as measured on Earth (in kilograms).
Mercury
Venus
Earth
Moon
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Choose the planet or moon to see your weight.
–.– kg
Weight on Earth: –.– kg
Gravity Factor: –.– x Earth
Mass (Constant): –.– kg
Formula Used: Your weight on another celestial body is calculated by multiplying your Earth weight by the ratio of that body's surface gravity to Earth's surface gravity (Weight = Earth Weight × (Body Gravity / Earth Gravity)). Your mass (the amount of matter in your body) remains constant regardless of gravity.
Weight Comparison Across Celestial Bodies
Your weight on various celestial bodies relative to Earth.
Weight Comparison Table
Celestial Body
Surface Gravity (m/s²)
Gravity Factor (vs Earth)
Your Weight (kg)
This table shows how your weight changes across different celestial bodies, factoring in their unique gravitational pull compared to Earth's.
What is Calculating Weight in Different Gravities?
Calculating weight in different gravities is a fundamental physics concept that helps us understand how gravitational forces affect objects on various celestial bodies. Unlike mass, which is an intrinsic property of an object and remains constant, weight is the force exerted on an object due to gravity. This means that while you are composed of the same amount of "stuff" everywhere in the universe, your perceived heaviness, or weight, will change significantly depending on the gravitational pull of the planet, moon, or star you are on. This calculator provides a simple way to explore these differences, helping to visualize the impact of gravity on your body.
Who should use it?
Anyone curious about space, physics, or how their own body would feel on other worlds. Students learning about gravity and mass, science enthusiasts, and even science fiction writers can find this tool insightful. It's particularly useful for educators demonstrating the difference between mass and weight in a tangible way.
Common misconceptions
A primary misconception is the confusion between mass and weight. People often say "I weigh 70 kilograms," which technically refers to their mass. Their weight, measured in Newtons, is mass multiplied by gravitational acceleration. However, in common parlance, "weight" is used to refer to mass, and kilograms are the unit. This calculator uses kilograms for simplicity, aligning with common usage, but clarifies the underlying physics. Another misconception is that gravity is uniform across a celestial body; while this calculator uses average surface gravity, real gravitational fields can have minor variations. The concept of calculating weight in different gravities is key to understanding these distinctions.
Weight in Different Gravities Formula and Mathematical Explanation
The core principle behind calculating weight in different gravities lies in the universal law of gravitation, but for practical purposes at a planet's surface, we simplify it. Weight ($W$) is directly proportional to the gravitational acceleration ($g$) of the location and the object's mass ($m$):
$W = m \times g$
Where:
$W$ is the weight of the object (force).
$m$ is the mass of the object (amount of matter).
$g$ is the acceleration due to gravity at that location.
Since mass ($m$) is constant for an object, its weight will change if $g$ changes. We typically measure our mass on Earth, where the average surface gravity ($g_{\text{Earth}}$) is approximately 9.80665 m/s². When we talk about "weight" in kilograms in everyday conversation, we are usually referring to mass. This calculator uses your Earth "weight" (mass) to determine your weight on other celestial bodies.
The formula to find your weight on another celestial body ($W_{\text{body}}$) using your Earth weight ($m$, commonly referred to as Earth Weight) is:
$W_{\text{body}} = m \times g_{\text{body}}$
Or, expressed as a factor relative to Earth:
$W_{\text{body}} = m \times (g_{\text{body}} / g_{\text{Earth}}) \times g_{\text{Earth}}$
Since $(g_{\text{body}} / g_{\text{Earth}})$ represents how much stronger or weaker the gravity is compared to Earth, we can call this the "Gravity Factor". Your resulting weight in kilograms on the other body will be your Earth mass multiplied by this Gravity Factor.
Variable Explanations:
Variable
Meaning
Unit
Typical Range (for planets/moons)
$m$ (Earth Weight)
The mass of the object, typically measured on Earth.
kg
N/A (user input)
$g_{\text{body}}$
The acceleration due to gravity on the surface of the celestial body.
m/s²
~0.1 (Moon) to ~24.8 (Jupiter)
$g_{\text{Earth}}$
The average acceleration due to gravity on Earth's surface.
m/s²
~9.81
Gravity Factor
The ratio of a celestial body's gravity to Earth's gravity.
Unitless
~0.16 (Moon) to ~2.5 (Jupiter)
$W_{\text{body}}$ (Weight on Body)
The calculated weight of the object on the specified celestial body.
kg
Varies based on input and Gravity Factor
Practical Examples (Real-World Use Cases)
Understanding calculating weight in different gravities helps in various scenarios, from space travel planning to educational demonstrations.
Example 1: Astronaut Training
An astronaut candidate weighs 85 kg on Earth. During training, they need to understand how this translates to lunar conditions.
Input: Earth Weight = 85 kg
Selected Body: Moon
Calculation: The Moon's surface gravity is approximately 1.62 m/s², while Earth's is about 9.81 m/s². The Gravity Factor is 1.62 / 9.81 ≈ 0.165.
Output: Weight on Moon = 85 kg × 0.165 ≈ 14.0 kg.
Interpretation: The astronaut would feel significantly lighter on the Moon, weighing only about 14 kg. This affects their movement, balance, and the design of spacesuits and equipment for lunar missions. This calculation is a core part of calculating weight in different gravities for mission planning.
Example 2: Martian Exploration
A rover designed for Mars has a base weight of 500 kg on Earth. Mission planners need to know its weight on Mars to ensure landing systems and mobility mechanisms are adequate.
Input: Earth Weight = 500 kg
Selected Body: Mars
Calculation: Mars' surface gravity is approximately 3.71 m/s². The Gravity Factor is 3.71 / 9.81 ≈ 0.378.
Output: Weight on Mars = 500 kg × 0.378 ≈ 189 kg.
Interpretation: The rover would weigh considerably less on Mars, about 189 kg. This reduction in weight is crucial for designing the rover's suspension, wheels, and the thrust needed for potential ascent vehicles. Understanding calculating weight in different gravities is vital for spacecraft and equipment engineering.
How to Use This Weight in Different Gravities Calculator
Using our calculator is straightforward and provides instant results.
Enter Your Earth Weight: In the first input field, type the weight you have measured on Earth. Use kilograms (kg) for accuracy. For instance, if you weigh 65 kg, enter "65".
Select a Celestial Body: Use the dropdown menu to choose the planet, moon, or dwarf planet (like Pluto) you are curious about. The calculator defaults to Earth, showing your current weight.
View Your Results: As soon as you select a body, the calculator automatically updates:
Main Result: Your calculated weight in kilograms on the selected celestial body, highlighted prominently.
Weight on [Body Name]: The specific weight for the chosen location.
Gravity Factor: How much stronger or weaker the gravity is compared to Earth (e.g., 0.378x Earth gravity).
Mass (Constant): Your unchanging mass in kilograms, reinforcing the difference between mass and weight.
Explore the Table and Chart: Scroll down to see a comparative table and a dynamic chart visualizing your weight across multiple celestial bodies. This offers a broader perspective on gravity's effects.
Use Additional Features:
Copy Results: Click the 'Copy Results' button to copy all calculated values and key assumptions to your clipboard for reports or notes.
Reset: Click 'Reset' to return the calculator to its default state (70 kg on Earth).
Decision-Making Guidance: While this calculator is for informational purposes, the results can help conceptualize the challenges and unique environments of space exploration. For instance, understanding the lower gravity on Mars informs decisions about rover design and astronaut physical conditioning for future missions.
Key Factors That Affect Weight in Different Gravities Calculations
While the core calculation is simple multiplication, several factors contribute to the accuracy and context of these results, especially when considering real-world applications beyond basic physics:
Accurate Mass Measurement: The primary input is your "Earth weight," which we interpret as mass. Ensuring this measurement is accurate is crucial. Variations in scales or measurement time (e.g., after meals) can slightly alter the input mass.
Surface Gravity Values: The $g$ values for celestial bodies are averages. Planets like Jupiter are gas giants, and their "surface" gravity is complex. For rocky bodies, gravity can vary slightly based on altitude and local density variations (mountains vs. valleys). The values used are standard, accepted averages. This is a key aspect of calculating weight in different gravities.
Atmospheric Pressure (Indirect Effect): While atmospheric pressure itself doesn't directly change your weight (which is mass * gravity), it can affect buoyancy. In dense atmospheres like Venus, buoyancy might make you *feel* slightly lighter, though your mass and true weight remain the same. This calculator doesn't account for buoyancy.
Orbital Mechanics and Altitude: Gravity decreases with the square of the distance from the center of a celestial body. The $g$ values used are for the surface. If you are in orbit or at a high altitude, your effective weight (and the gravitational force acting on you) will be less. This calculator assumes surface-level gravity.
Rotation of the Body: The rotation of a planet creates a centrifugal force that slightly counteracts gravity, making objects weigh less at the equator than at the poles. Earth's equatorial gravity is about 0.5% less than its polar gravity. This calculator uses a standard average $g$ value that doesn't account for rotational effects.
Tidal Forces: For objects close to massive bodies (like moons orbiting planets), tidal forces can exert differential gravitational pulls, stretching objects. While not directly affecting the calculated weight in the same way as surface gravity, it's a related gravitational phenomenon.
Definition of "Weight": As mentioned, common usage conflates mass and weight. This calculator provides results in kilograms, aligning with common parlance, but the underlying physics distinguishes between mass (amount of matter) and weight (force due to gravity). Accurate calculations of weight in different gravities hinge on understanding this distinction.
Frequently Asked Questions (FAQ)
Q: Is my weight the same as my mass?
No. Mass is the amount of matter in an object and is constant everywhere. Weight is the force of gravity acting on that mass, and it changes depending on the gravitational pull of the location. Your mass is always the same, but your weight varies. This calculator helps illustrate calculating weight in different gravities.
Q: What is the gravity on Jupiter compared to Earth?
Jupiter has a much stronger gravitational pull than Earth. Its surface gravity factor is about 2.43 times that of Earth. So, if you weigh 70 kg on Earth, you would "weigh" approximately 70 kg * 2.43 = 169.9 kg on Jupiter (assuming you could stand on its 'surface').
Q: Why does the calculator show my mass as constant?
The calculator highlights your mass because it's a fundamental physical property that doesn't change with location. The "Weight on [Body Name]" result is your gravitational force experienced there, converted back to a kilogram equivalent for easy comparison, but your actual mass remains unchanged.
Q: Can I use this calculator for stars like the Sun?
This calculator is designed for planets and moons with measurable surface gravity. Stars like the Sun have immense gravity, but it's not a "surface" in the same sense, and the gravitational forces and conditions are vastly different and more complex. The values used here are not applicable to stellar bodies.
Q: What does a gravity factor of 0.16 mean?
A gravity factor of 0.16 means the gravitational pull of that celestial body is about 16% of Earth's gravity. For example, the Moon's gravity factor is approximately 0.165, which is why astronauts appear to 'bounce' and feel much lighter when walking on the lunar surface.
Q: Does the calculator account for atmospheric buoyancy?
No, this calculator focuses solely on the force of gravity acting on your mass. It does not account for buoyancy effects that might occur in dense atmospheres (like Venus or Jupiter), which can make objects feel slightly lighter.
Q: How are the gravity values determined?
The surface gravity values used are based on scientific measurements and calculations derived from the mass and radius of each celestial body. These are widely accepted scientific figures used in astronomy and physics.
Q: Can I calculate weight for fictional planets?
This calculator uses real astronomical data for known celestial bodies. It cannot be used for fictional planets unless you manually input a custom gravity value, which is not a feature of this specific tool. However, the underlying formula ($Weight = Mass \times Gravity Factor$) can be applied.
Related Tools and Internal Resources
Gravity Calculator: Explore our dedicated tool for in-depth gravity calculations.