What is an equation that relates weight on earth and weight on the moom

W=mg 

Where: 

Weight = mass * acceleration due to gravity 

So let's say I want to work out my weight on the moon. I know I weigh about 70kg (which would be N), but I can't use that figure for the calculation on the moon. That is what I weigh on Earth, so let's look at the equation... 

70kg = mass * 9.81m/s^2 

Where 9.81m/s^2 is the acceleration due to gravity on the surface on the earth. I want to get rid of that, so let's work out my mass by division; 

70/9.81 = 7.14kg 

I googled the acceleration of gravity on the Moon, which was = 1.6m/s^2 

Let's use that in the same equation W=mg 

W = 7.14kg * 1.6m/s^2 = 11.42N

On the Moon, you would weigh approximately one sixth of your weight on Earth, so if your bathroom scales tell you you weigh 120 pounds, there you would weigh 20 pounds.

Moon`s gravitational pull is about one-sixth to the gravitational pull on earth hence weight on moon is about one-sixth of the weight on earth.