how many gallons of paint will be needed to paint a 1600 square foot interior of a home
12,800 / 200 = 64 Add 1600 for celings You need 72 gallons of paint. If 1600 is the amount of wall space that needs to be painted, double that for the ceilings = 3200 / 200 = 16 gallons of paint. Source(s): Owner and operator of a painting company for 15 years, husband is a painter/faux finisher of 30 years.Michelle L Â· 8 years ago.dd to that the 1600 sq ft of ceiling area.. 4. that is how many sq ft of primer you need...if your walls are really bad...2 coats of primer may be needed... 5. Double you answer form 3, that is how much paint you need...I always use 2 coats...