Planet Surface Gravity Calculator
Result
Gravity (Earth g)0.3780598112
Gravity (m/s²)3.7075002473
↗ Space
Estimate surface gravity from a planet’s mass and radius relative to Earth.
Formula
g / gEarth = Mass ratio ÷ Radius ratio²
- Enter mass in Earth masses and radius in Earth radii. Surface gravity scales as mass divided by radius squared.
- The main inputs are Mass, Radius. Enter them in the units and format shown in the calculator.
- Use the units, labels and assumptions shown beside each input so the formula is applied consistently.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Planet Surface Gravity
Inputs
- Mass: 0.107 Earth masses
- Radius: 0.532 Earth radii
A body with 0.107 Earth masses and 0.532 Earth radii gives about 0.378 g, close to Mars.
Sample result: Calculating…
Frequently asked questions
What does this calculator estimate?
It estimates surface gravity from mass and radius ratios.
Is this an exact mission-planning tool?
No. It is an educational calculator based on the stated constants and simplified assumptions.
How accurate is the result?
The spherical-body approximation is very good for broad planetary comparisons but ignores rotation and local geology.
What does the Planet Surface Gravity calculate?
Estimate surface gravity from a planet’s mass and radius relative to Earth.
Which values should I enter?
Enter Mass, Radius using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: g / gEarth = Mass ratio ÷ Radius ratio².