Well to calculate area we use the equation: **( Height ) x ( Length )**

12 x 120 = 1440 meter squares, this is the total area of the wall

Now since each paint gallon covers 150 feet square, we can simply divide 1440 by 150 :

1440 / 150 = 9.6 gallons

Now you can't really buy 9.6 gallons at Home Depot! So we will round to **10 total gallons** of paint needed