ONE FORMULA, ONE ANSWER
Escape Speed Calculator
Calculate the minimum initial speed to escape an isolated body. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Escape speed v_esc
Enter values and select Calculate.
v_esc = √(2GM/r)
Assumptions
Required: M,r>0 and an exterior spherical Newtonian gravity field. Use center distance, not altitude. Excluded: atmosphere, rotation, other bodies and continued thrust. Results at or above light speed are rejected.
Displayed values are floating-point approximations. Design safety factors and unprovided error contributions are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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