how many gallons of paint will it take to paint an average sized house. its 1600 sq feet
Your probably looking at about 15- 20 gallons for two coats. Start out with less because almost all colors now are custom tint and are not returnable. You can always buy more if you need it. Or just do the math measure the room length times width times height. Average 10 X12 room 8 ft high including ceiling 472 sq. ft divided by 350 sq. ft per gallon about 1.5 gallons for one coat.
Exterior or interior? Going to scrape/sand/prime it first? 1600 square feet doesn't give much information...a house with 10' or 14' ceilings (= taller walls = more surface = more paint) will need more paint than a house with 8' ceilings. For the interior, measure the height and length of all the walls, 'rounding up' to the next foot: height x length = square feet of wall surface. Length and width measurement of the floor will give you the square foot surface of the ceiling. Add up all those figures, that's your interior square foot surface area. Then go to a paint store and look on the cans of paint: it will have a section on the label saying Coverage, which will say something like A gallon covers 200 square feet depending on the paint. Talk to the paint store people, give them your square footage figures, tell them what you're painting, ask for tips, recommendations, things NOT to do, etc. Armed with paint rollers, brushes, buckets, masking tape (I prefer the 'delicate surface' type...doesn't peel the paint off of painted walls), plastic tarps, etc., etc., have fun.
Paint coverage differs with the type and maker of the paint. In general oil base paint covers more area than latex base but again, it differs with the maker of the paint. Check at your local paint supply store or read the label on the paint container for approx. coverages. Depending on what the surface of the house is and the color change, more than one coat may be required.
You did the mathematics wrong. You need to equate it by linear ft. It depends on the number of walls which you are going to paint. the length and height of each wall as well because if you have high ceilings you will need more paint. But on average I would say about 4 gallons per room.
You need to compute your sq. ft. of each wall, then read the can. It should give you the coverage area. Most cans have this info on them. If you are changing colors you may need more. you can then double the amount. Any cans you do not use maybe returned for you money back. ( unless it is a special mix) Most important make sure the colors are from the same batch and run, unless it is white, it should not matter.
