Physics

Escape Speed Calculator

Estimate escape speed from a spherical body without atmosphere.

SI units shown beside each fieldIdeal model explained below
Physics lab
Physics lab

Use the units beside each input and review the model assumptions.

See the method

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Your calculated quantity

Your result

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Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter central body mass, distance from center.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

Input reference and sample values

Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.

InputFormat and unitsSample
Central body massNumeric value. Unit: kg. Must be greater than zero.5.972e+24
Distance from centerNumeric value. Unit: m. Must be greater than zero.6371000

Result for these sample inputs

11185.9779 m/s

Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.

The method, explained

Escape speed = √(2GM/r); G = 6.67430 × 10⁻¹¹.

A WORKED EXAMPLE

Using central body mass = 5.972e+24 kg, distance from center = 6371000 m, the result is 11185.9779 m/s. Change these example inputs to match your task; use the method above to check each step.

What to keep in mind

Newtonian model ignoring other bodies and propulsion losses. An idealized educational model using the stated SI units. Real systems may need additional forces, losses or experimental measurements. Not a safety or equipment specification.

Methodology maintained by ClarityKit. How these tools are built and checked.