Painting guides
The calculators give you the number. These pages give you the why, so you can argue with the number when your walls deserve it.
How much does a gallon of paint cover?350 to 400 sq ft on smooth walls, 200 on stucco, plus paint per square foot.
One coat or two?When one is honest, when two is mandatory, and when the wall wants three.
Measuring a room for paintPerimeter, height, deductions, and the stairwell problem, with a worked example.
Do I need primer?The five cases that need it, the one that doesn't, and which primer for which mess.