Skip to content
Calculator Collection

Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Astronomy

Schwarzschild Radius Calculator

Compute the Schwarzschild radius — the event horizon size of a non-rotating black hole — from its mass via r_s = 2GM/c². The defining length scale of black holes, equal to about 3 km per solar mass.

Fill in the required fields to see your result.
Astronomy

Redshift Velocity Calculator

Compute the recession velocity of a nearby galaxy from its redshift z using v = c·z, where c is the speed of light. Part of the Hubble-Lemaître law — the empirical relation that established the expanding universe.

Fill in the required fields to see your result.

Key differences

Schwarzschild Radius CalculatorRedshift Velocity Calculator
CategoryAstronomyAstronomy
Inputs required11
ResultSchwarzschild Radius (km)Recession Velocity (km/s)
What it doesCompute the Schwarzschild radius — the event horizon size of a non-rotating black hole — from its mass via r_s = 2GM/c². The defining length scale of black holes, equal to about 3 km per solar mass.Compute the recession velocity of a nearby galaxy from its redshift z using v = c·z, where c is the speed of light. Part of the Hubble-Lemaître law — the empirical relation that established the expanding universe.