Calculating a planet's mass & gravitational pull

[dogscoff]

Thanks S_J- a few questions:

kg/m^3 x m^3 = kg

So that's kilograms per metre cubed times metres cubed. My "volume" value is in kilometres cubed, so do I just divide by 1000 to get metres cubed?

Where gravitational constant G = 6.67300 × 10-11 m3 kg-1 s-2

Glurp! so if my distant maths lessons are correct, that would be -6.67300 with the decimal place moved 11 spaces to the right. Correct? What does the kg-1 s-2 mean?

A = GM/R^2

so M in this one is the mass of the planet as calculated above.

If I run Earth's vital statistics through the above treadmill I should get a value somewhere near 1, is that right?