You’ve decided to paint your room instead of using wallpaper. You know you will need to apply two coats of paint to fully cover the walls. One gallon of paint will cover 400 square feet. How many quarts of paint will you need to purchase if there are 4 quarts in a gallon?

Answer 1

depends on the size of the walls ...
double the area and divide by 100 to find the quarts needed (round up)