Calculating your surface gravity is straightforward once you know the Surface Gravity formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Surface Gravity Calculator.
What is Surface Gravity?
The Surface Gravity calculation tells you your surface gravity from a few simple inputs. The figure you are solving for here is the surface gravity.
The Surface Gravity formula
The core formula is:
Surface gravity = 0.00000000006674 × Mass of the body ÷ (Radius × 1000) ^ 2Here is what each input means:
- Mass of the body — a value measured in kg. Example: 5,972,000,000,000,000,327,155,712 kg.
- Radius — a value measured in km. Example: 6,371 km.
How to calculate it step by step
- Write down the mass of the body (for example, 5,972,000,000,000,000,327,155,712 kg).
- Write down the radius (for example, 6,371 km).
- Apply the formula above to get your surface gravity.
- Double-check the result with the Surface Gravity Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Mass of the body | 5,972,000,000,000,000,327,155,712 kg |
| Radius | 6,371 km |
| Surface gravity | 0.000 |
| Compared to Earth (g) | 0.000 |
With mass of the body of 5,972,000,000,000,000,327,155,712 kg and radius of 6,371 km, the surface gravity works out to 0.000.
Example 2
With mass of the body of 11,999,999,999,999,999,798,673,408 kg and radius of 6,371 km, the surface gravity works out to 0.000.
| Result | Value |
|---|---|
| Surface gravity | 0.000 |
| Compared to Earth (g) | 0.000 |
Example 3
With mass of the body of 2,999,999,999,999,999,949,668,352 kg and radius of 6,371 km, the surface gravity works out to 0.000.
| Result | Value |
|---|---|
| Surface gravity | 0.000 |
| Compared to Earth (g) | 0.000 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Surface Gravity Calculator does it instantly, for free, with the formula and a worked example built in.
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