Examples: 
•The Schwarzschild Radius:
–Mass in solar masses Rs (km)
•10 30
•3 9
•2 6
•1 3
•0.000003 (Earth) 0.9 cm
In metric units, G = 6.67 x10-11,  c=3x108, 1 solar mass = 2x1030 kg
Then Rs is in meters