Black Hole Schwarzschild Radius Calculator: Astr...
Calculate the Schwarzschild radius (event horizon) of any mass — from particles to stars. Understand how extreme gravity creates black holes and the physics of no...
What is the Schwarzschild Radius?
The Schwarzschild radius (rs) is the critical radius at which an object's escape velocity equals the speed of light. If any object is compressed to within this radius, it becomes a black hole — light itself cannot escape. Named after physicist Karl Schwarzschild who derived it in 1916 from Einstein's field equations.
🕳️ Schwarzschild Radius Calculator
Use our free calculator for instant, accurate results.
📐 Formula
rs = 2GM / c²
G = 6.674×10⁻¹¹ N·m²/kg² (gravitational constant), M = mass (kg), c = 3×10⁸ m/s (speed of light).
📝 Worked Example
Schwarzschild radius of the Sun (M = 1.989×10³⁰ kg):
rs = 2 × 6.674×10⁻¹¹ × 1.989×10³⁰ / (3×10⁸)²
rs ≈ 2,953 m ≈ 3 km
(The Sun would need to be compressed to 3 km to become a black hole)
📝 How to Use the Calculator
❓ FAQ
What is at the Schwarzschild radius?
It marks the event horizon — the point of no return. No information or matter can escape from inside this boundary.
Can a proton become a black hole?
Theoretically yes — its Schwarzschild radius is ~2.5×10⁻⁵⁴ m, far smaller than a proton itself. This is a thought experiment, not something that happens naturally.
Veer Kumavat
Founder & AuthorVeer is a 14-year-old student from Nashik, Maharashtra, who built SciFi Calculators to help students worldwide master STEM subjects. He is passionate about making complex science and math problems accessible through intuitive digital tools.