Calculate schwarzschild radius (gravitational radius) of a sphere using simple astronomy calculator online.
Formula:
rs = [2ā¢Gā¢M / cĀ²]
where,G = gravitational constant (6.67*10-11 Newton-meter2 / kg2),
m = the mass of the body (kg),
c = the speed of light (299792458 m/s),
rs = the schwarzschild radius