698 tools
All

Schwarzschild Radius Calculator

Find Rs = 2GM/c², the event-horizon scale of a non-rotating black hole.

 

Rs (m)

About this calculator

Use this calculator for the Schwarzschild radius of a non-rotating, uncharged mass: Rs = 2GM/c². Anything that fits inside its Schwarzschild radius can be a black hole in this model.

For one solar mass (~1.99×10³⁰ kg) Rs is about 3 km. Earth would be a few millimetres. Spin (Kerr) and electric charge change the horizon; they are ignored here.

Mass (kg): Mass in kilograms. The Sun is about 1.989×10³⁰ kg.

Rs (m): Schwarzschild radius in metres.