Schwarzschild Radius Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026The boundary where light itself cannot escape
The Schwarzschild radius defines a black hole's event horizon - compress any mass down within this radius, and its gravity becomes strong enough that not even light can escape from within it.
Worked example
For one solar mass:
Rs = 1 x 2.95 = 2.95 km
This means compressing the Sun's entire mass down into a sphere just 2.95 km in radius (compared to its actual radius of roughly 696,000 km) would be enough to turn it into a black hole - a striking illustration of how extreme the density requirement actually is.
Since Schwarzschild radius scales directly with mass, a black hole with 10 times the Sun's mass has an event horizon 10 times larger, roughly 29.5 km.