How to use the surface gravity of a planet calculator
Compute gravity at a planet's surface from mass and radius. Enter mass, radius in the fields above; the surface gravity, surface gravity are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- M — Mass (Earth masses)
- r — Radius (Earth radii)
Worked example
With mass = 1 Earth masses, radius = 1 Earth radii, the calculator gives surface gravity ≈ 9.820302 m/s²; surface gravity ≈ 1.001392 g.
Frequently asked questions
What is the formula for the surface gravity of a planet calculation?
Surface gravity (m/s²) = GCONST × M × MEARTH / (r × REARTH)^2. Surface gravity (g) = [Surface gravity] / GRAV. Here M is mass (Earth masses), r is radius (Earth radii).
What inputs do I need for the surface gravity of a planet calculator?
You need mass in Earth masses, radius in Earth radii. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.