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Planet Density Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Mean density
5,513.3
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Planet Density Calculator
The Planet Density Calculator works out your mean density in an instant. Enter mass and radius and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the mass.
- Enter the radius.
- Read off your mean density — the calculator updates automatically, with no button to press.
Formula
The Planet Density Calculator uses the formula:
Mean density = Mass ÷ (4 ÷ 3 × 3.141592653589793 × (Radius × 1000) ^ 3)
Worked example
For example, with mass of 5,972,000,000,000,000,327,155,712 kg and radius of 6,371 km, the mean density is 5,513.3.
| Mass | 5,972,000,000,000,000,327,155,712 kg |
|---|---|
| Radius | 6,371 km |
| Mean density | 5,513.3 |
|---|
Results are estimates for educational use, not professional advice.
Key terms explained
- Density
- Mass per unit volume, calculated as mass ÷ volume.
- Mean
- The average of a set of numbers — their sum divided by how many there are.
- Radius
- The distance from the centre of a circle or sphere to its edge.
Frequently asked questions
Divide mass by the volume of a sphere, 4⁄3 πr³. Earth's mass and radius give a mean density of about 5,513 kg/m³.
It hints at composition. Rocky planets are dense (around 5,000 kg/m³), while gas giants are far less dense.
Earth is the densest planet in the Solar System. Saturn is the least dense — it would float in water.
A planet's density varies with depth, so the mean gives a single representative value from total mass and volume.
Enter the mass. Enter the radius. Read off your mean density — the calculator updates automatically, with no button to press.
Related guides
Planet Density Table: Mean density by Mass
Reference table of mean density for Planet Density across a range of mass values — exact, engine-computed figures you can read off at a glance.
How to Calculate Planet Density: Formula, Steps & Examples
Learn how to calculate Planet Density — the formula explained step by step, with worked examples and a free calculator to check your answer.