Schwarzschild radius calculator

Inside the Schwarzschild radius, the escape velocity would exceed the speed of light, so nothing can get out. It grows in a straight line with mass: about 3 km for each solar mass. Earth squeezed into a sphere about 9 mm across would become a black hole; the Milky Way’s central black hole, at 4.3 million solar masses, has a horizon about 12.7 million km across.

1. 2 × G × M ÷ c² (kg, m) 2 × 6.6743 × 10⁻¹¹ × 1 M☉ ÷ (299,792,458 m/s)² = 2,953.339382 m