⚠ Extreme Gravity — Do Not Approach

Black Hole Event Horizon Radius Calculator

Constants: M☉ = 1.988416×10³⁰ kg · R☉ = 695,700 km

Calculates the Schwarzschild radius, the boundary beyond which nothing, not even light, can escape, for any mass using R = 2GM/c². Enter a mass in solar masses, Earth masses, or kilograms to find its event horizon radius instantly.