Following a few simple steps will help you calculate the amount of paint you will need to complete the job. Don’t forget to account for windows and doorways when measuring walls. And don’t forget to double the final amount if you plan to apply two coats.

	Start by measuring the room you want to paint.
	Enter the correct number in feet (round up to the nearest foot) in each of the boxes to the right. wall width 1   * ceiling length wall width 2   * ceiling width wall width 3   * Enter 0 if you are not painting the ceiling. wall width 4
	Enter your ceiling height here.
	Then click the calculate button.

If you follow these simple steps, excess paint should be minimized and can easily be disposed of in accordance with local, state, and federal regulations.