**35+ Cost Per Square Foot To Paint Interior Walls**. One gallon of paint covers approximately 400 square feet. If you're doing the ceilings, walls and trim, the cost per square foot will likely fall between $3 and $4.

Estimate the cost of materials. A gallon of interior paint covers on average 400 square feet. Three gallon cans of paint cover up to 1200 square feet.

### Interior painting cost calculator estimates how much it costs to paint the interior of your house per square foot.

Prices in london are likely to be a little higher. What is the interior painting cost per square foot? Windows average 15 square feet (there are two in this example): In this blog we discuss how much it costs to paint our price for painting two coats on the walls of the noted areas is about $4,000 to $4,500.