Gravitational Potential Energy in Orbit Calculator

Gravitational Potential Energy in Orbit Calculator

Compare orbital potential energy, delta U, circular kinetic energy, and total orbital energy between two radii around a selected central body.

🛰Real orbit presets
Orbit energy inputs
The calculator converts to SI units internally.
Use spacecraft, satellite, payload, or test mass.

Orbit energy results

Initial potential energy - U1 = -G M m / r1
Target potential energy - U2 = -G M m / r2
Delta potential energy - Delta U = U2 - U1
Circular total energy change - Delta E = -GMm/(2r2) - E1
📊Current comparison grid
6,778 km Initial radius
7.67 km/s Target circular speed
1.003x Radius ratio
3.00e10 J Target escape energy
🌐Central body constants
Central body Mass (kg) Mean radius (km) GM, mu (m³/s²)
Earth5.9722e246,378.13.9860e14
Moon7.342e221,737.44.9049e12
Mars6.4171e233,389.54.2828e13
Jupiter1.8982e2769,9111.2669e17
Sun1.9885e30695,7001.3271e20
Venus4.8675e246,051.83.2486e14
Mercury3.3011e232,439.72.2032e13
Saturn5.6834e2658,2323.7931e16
📐Formula breakdown
Quantity Formula Meaning Sign check
Potential energyU = -G M m / rEnergy relative to zero at infinityAlways negative for bound radii
Delta potentialDelta U = U2 - U1Change between two orbital radiiPositive when radius increases
Circular kineticK = G M m / (2r)Kinetic energy for a circular orbitPositive
Total circular energyE = -G M m / (2r)Mechanical energy K + UHalf of U
Circular speedv = sqrt(GM/r)Speed for a circular orbit at radius rFalls as r increases
Escape from circular orbitDelta E = G M m / (2r)Extra energy to reach zero total energyEquals circular kinetic energy
🛸Earth orbit comparison table
Orbit example Altitude Radius from center U per 1,000 kg Circular speed
Low Earth orbit400 km6,778 km-5.88e10 J7.67 km/s
Sun synchronous700 km7,078 km-5.63e10 J7.50 km/s
Medium Earth orbit20,200 km26,578 km-1.50e10 J3.87 km/s
Geostationary35,786 km42,164 km-9.45e9 J3.07 km/s
Lunar distance384,400 km390,778 km-1.02e9 J1.01 km/s
🔢Delta U quick lookup
Central body Move Mass Approx delta U
Earth400 to 420 km1,000 kg1.73e8 J
Earth400 to 700 km1,000 kg2.49e9 J
EarthLEO to GEO1,000 kg4.94e10 J
Moon100 to 3,000 km10,000 kg1.73e10 J
Mars300 to 400 km1,000 kg3.20e8 J
Jupiter5,000 to 80,000 km1,000 kg8.83e11 J
💡Orbit energy tips
Radius tip: Orbital potential energy uses distance from the center of the central body. If you enter altitude, the calculator adds the selected body's mean radius before applying U = -G M m / r.
Interpretation tip: Raising an orbit makes gravitational potential energy less negative, so Delta U is positive. Lowering an orbit makes Delta U negative even though circular speed usually increases.

Built for JSCalc-Blog.com with SI physics constants and direct orbital-energy equations. Real mission-like presets are simplified to circular-radius comparisons.

We usually think of gravity as a force that pulls us down. But it is more complex than that; it is actualy the opposite of what you would expect.

Sending up a satellite isn’t like lifting an object that are constantly being weighed down by its own gravity. We’re climbing away from a deep well of potential. Every kilometer higher require a different kind of effort.

Understanding Gravity and Orbital Energy

This change, and knowing how to model it. Makes the difference between a feasible mission plan rather than just a shot-in-the-dark guess.

Plug in your altitude and your mass into the calculator, and let it crunch the numbers for you. No need to bother with conversions or coefficients… The calculator takes care of that part.

Where it gets interesting is when you start understanding what all these number mean. But gravitational potential energy are negative. Always. And we set it so that zero energy is infinitely far away. At that point gravity doesn’t have any hold over you.

You need to put some energy into it to get there. If you are above surface of the earth (like a satellite in Low Earth Orbit) then your energy level is not as bad as someone on the ground. But it’s still very much below zero.

As you raise your orbit that potential energy becomes less and less negative. People gets confused about this. They think raising means getting more energy. In physics terms that’s correct, but now you’re climbing out of a deep valley towards a flatter plain. The difference is positive. Total remains negative until you escape completely.

And think about the energy. How much of it is potential and how much is total? The virial theorem state that if an object is in a stable orbit its kinetic energy will be exactly one-half the magnitude of the potential energy. For a circular orbit kinetic energy is half the magnitude of potential energy.

But what does this imply about the total mechanical energy? Well, since we know it’s negative and potential is twice the total energy, then… Yep, still negative. And it equals half the potential.

So, to get off the planet, you require enough energy to go from whatever your current energy level is to having zero total energy. This means adding enough energy to what you already have to remove your binding energy.

The tool includes options to look at all of this and see the full picture. You can also toggle back and forth between looking at changes in potential alone. You can even look at escape requirements and kinetic.

Why should you care about the difference when planning out burns? A little nudge to increase your apogee might look cheap in terms of potential. If you’re wanting to circularize there once you’ve increased your apogee you’ll need to account for the decrease in speed as well.

Notice all the preset in the interface. To reach a bit higher up from where International Space Station is, it only takes a little bit of extra power. Take the same mass out into Geostationary Orbit though, and the cost goes through the roof.

It’s less about how much altitude you move, and more about the radius. The formula is 1/r², which is the inverse off the distance from the center of the Earth. If you double the distance from the center, the strength of the potential is cut in half.

That geometric relationship is why the cost of getting into deep space goes up exponentially. You’re not just battling against gravity; you’re battling against the shape of the energy well itself.

The reference data has some real-world applications as well. We’re used to the parameters of Earth. But now we can use this calculator to find values for Mars, the Sun, and even Jupiter.

Yes, the same principles apply. The scales is very different, though. Because of its mass, it takes a lot more energy to get to orbit around Jupiter. On paper, orbital mechanics appear to be roughly the same.

The trick is getting the right radii and units. If you’re working with surface height, then always include the radius of the body. Otherwise, the inverse-square logic gets thrown out the window and gives you results that seem reasonable but aren’t possible.

It’s about managing budgets of energy. If you’re an engineer sizing a propulsion system or a student double-checking your homework, the trade-off is obvious. Good coverage come from higher orbits. Reaching them requires a lot of energy. Accessing lower ones is cheap. Keeping them requires constant reboosts.

The math couldn’t be simpler. The meaning could not be more profound.

Position costs you fuel. Each joule matters. Remember that negative sign. It is not just a mathematical formality. It is a reminder that orbit is an active state. It’s a delicate balance between flying and falling.

See the well. Once you’ve seen it, you’ll never un-see it.

You should of seen it sooner.

Gravitational Potential Energy in Orbit Calculator