Skip to content
Calculator Collection

Compare calculators

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

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.
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.

Key differences

Redshift Velocity CalculatorSchwarzschild Radius Calculator
CategoryAstronomyAstronomy
Inputs required11
ResultRecession Velocity (km/s)Schwarzschild Radius (km)
What it doesCompute 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.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.