gravity on mars

[mike123]

How strong is gravity on mars compared to Earth?
I know earth has around 9.8. How much is Mars? And on the Moon?

[granthutchison]

Your units for Earth are newtons/kilogram - in the same units Mars scores 3.7 and the Moon, 1.6: so about 1/3 and 1/6 of Earth, respectively.

Grant

[ElPelado]

You can calculate it easily:
g=G*M/r^2

g: gravity aceleration(what you want to know) in N/kg or m/s^2
G: gravity constant= 6.67e-11 in N*m^2/kg^2
M: Planet's/Moon's Mass in kg
r: Planet's/Moon's radius in meters

For Earth M=5.947e24 kg and r=6.38e6 m, so g~9.74 N/kg or m/s^2
For Mars M=0.642e24 kg and r=3.4e6 m, so g~3.7 N/kg or m/s^2

BTW: Newton/KiloGram=N/Kg
N=Kg*m/s^2
So Kg*m/Kg*s^2=m/s^2