Black Hole Radius (Schwarzschild) Calculator
Astronomy & SpaceCalculate the Schwarzschild radius (event horizon size) of a black hole based on its mass.
Schwarzschild Radius
The radius of the event horizon, the boundary beyond which nothing, not even light, can escape — approximately 2.95 km per solar mass.
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Frequently Asked Questions
What is the Schwarzschild radius?
The Schwarzschild radius defines the size of a black hole event horizon — if an object mass is compressed within this radius, its escape velocity exceeds the speed of light, forming a black hole.
Why is the conversion factor 2.95 km per solar mass?
This figure comes directly from the Schwarzschild radius formula (2 times the gravitational constant times mass, divided by the speed of light squared), evaluated using the Sun mass as a convenient reference unit.
Could the Sun become a black hole?
No — the Sun does not have enough mass to undergo the gravitational collapse needed to form a black hole. If it somehow were compressed to a black hole, its Schwarzschild radius would be only about 3 kilometers.
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