Amount of paint needed to cover the average-sized room, using a standard latex paint Room SizeGallons of Paint Needed small room (8′ x 8′) 1 gallon medium room (12′ x 12′) 2 gallons large room (18′ x 18′) 3 gallons bathroom 1 gallon kitchen 1-2 gallons bedroom 2 gallons ...
So, a room that's 650 square feet would need roughly two gallons of paint because 650 divided by 250 comes out to about 2.6. However, you always need two coats, so expect to buy around six gallons of paint for a room of this size.[3] 4 Figure out the cost of paint. Once you...