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Surface Gravity From Mass and Radius Calculator

Estimate gravitational acceleration at a spherical body’s surface from its mass and radius. This tool uses body mass (kg), body radius (m) as its stated inputs. The output is reported in m/s², so it should be compared only with figures in compatible units. Approximates a spherical nonrotating body; altitude, oblateness and rotation alter measured local acceleration.

How to use this calculator

  1. Measure or look up the input for body mass (kg) and check that its unit matches the field.
  2. Enter body radius (m). Change the supplied example numbers to match your own scenario.
  3. Read the calculation in m/s² and review the formula and limitations below before using it to make a decision.

How to calculate surface gravity from mass and radius

Surface gravity = G × body mass ÷ radius², with G ≈ 6.67430×10⁻¹¹ m³ kg⁻¹ s⁻².

  • The formula uses the supplied measurements directly and returns its primary result in m/s². No external data or background estimates are fetched by this calculator.
  • Use consistent reporting intervals and measurement units. A different unit or different definition for one input changes the meaning of the result.

Worked examples

Worked example: Surface Gravity From Mass and Radius

Consider the following example input values: Body mass (kg) = 5.972e24, Body radius (m) = 6371000.

Apply the stated relationship: Surface gravity = G × body mass ÷ radius², with G ≈ 6.67430×10⁻¹¹ m³ kg⁻¹ s⁻².

Using those inputs gives approximately 9.819973 m/s².

Understanding the result

The result of the worked example is approximately 9.819973 m/s²; it is an arithmetic outcome rather than a prediction of actual conditions.

Approximates a spherical nonrotating body; altitude, oblateness and rotation alter measured local acceleration.

Important notes

Approximates a spherical nonrotating body; altitude, oblateness and rotation alter measured local acceleration.

This result reflects the entered values only. Validate body mass (kg) against a relevant measurement or primary record; rounding, timing, or inconsistent units can affect practical decisions.

Frequently asked questions

What does the surface gravity from mass and radius calculator measure?

Estimate gravitational acceleration at a spherical body’s surface from its mass and radius.

What formula does this surface gravity from mass and radius calculator use?

Surface gravity = G × body mass ÷ radius², with G ≈ 6.67430×10⁻¹¹ m³ kg⁻¹ s⁻². Approximates a spherical nonrotating body; altitude, oblateness and rotation alter measured local acceleration.

Can I rely on this surface gravity from mass and radius calculator for a final decision?

First check the input units and whether the underlying assumption is appropriate. Approximates a spherical nonrotating body; altitude, oblateness and rotation alter measured local acceleration. For regulated or safety-critical decisions, verify with appropriate authoritative guidance.

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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.