How much paint is needed to cover a room12x14?

It depends on the height of the ceilings. If they are 10 feet, that would put the painted area at 420 square feet. Paint covers approx 350 - 400 square feet per gallon over a sealed surface, depending on the texture of the wall so it would take about 1 1/2 gallons of paint for one coat. Lower ceilings will use a little less, cathedral or tall ceilings more. Add in another gallon if you are painting the ceiling.