how do I calculate how many gallons of paint I will need? I can figure out how to get the square footage, but how many sq feet does a gallon of paint cover? or does it depend on the kind of paint? any professional painters out there?
Hey Ruby. Each brand of paint differs, and it IS in fact estimated on most cans as to what kind of coverage in sq ft per gallon you can expect. Of course, if you are painting something rough, porous, unprimed etc, it will really vary. I look to use about a gallon of good quality acrylic latex per average room (like, say, a 13 x 9 room), not including ceilings, where I look to use about a gallon per bedroom of oil-based flat white for a textured ceiling (they are very thirsty). If you are doing any more than about 2 bedrooms the same colour, buy a big 5 gal pail - even with some waste, it's much cheaper, and I find I do a better job if I know I'm not going to run out of paint. Always want some left for touch-ups too....
But top quality acrylic paint. The plastics in it harden in about 30 days and really make things much more durable. General Paint HP2000 is very good.
One thing to remember - if you think you might run short on a two coat job, you can always stretch the second coat with some water- especially on a textured surface. All the rules, tho, of paint calculation are subject to the actual conditions - I recently did a bedroom that ended up requiring a primer and two coats because the walls were in such bad shape.