ONE FORMULA, ONE ANSWER
Schwarzschild Radius Calculator
Calculate the horizon radius of a nonrotating uncharged black hole model. 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
Schwarzschild radius r_s
Enter values and select Calculate.
r_s = 2GM/c²
Assumptions
Required: M>0. This is the nonrotating uncharged Schwarzschild horizon radius. Excluded: spin, charge, disks and apparent shadow size. The result does not classify an observed object as a black hole.
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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