Paint Calculator

Find how many gallons you need to cover walls, ceilings, or trim. Supports single and double coat calculations with spread rate adjustment.

Paint estimating converts wall and ceiling area into gallons based on spread rate and number of coats. This calculator lets you adjust the spread rate for different surface textures and paint types. The result tells you exactly how many gallons to purchase, preventing both waste from over-buying and delays from mid-project re-orders.

Frequently Asked Questions

How much area does one gallon of paint cover?

Most interior latex paints cover 350–400 square feet per gallon on smooth surfaces. Textured walls, bare drywall, and porous surfaces may reduce coverage to 250–300 sq ft per gallon.

Do I need primer before painting new drywall?

Yes. New drywall absorbs paint unevenly without primer. Use a PVA (polyvinyl acetate) primer designed for new drywall to seal the surface before applying topcoats.

How many coats of paint do I need?

Two coats is standard for most residential applications. A single coat may work when repainting with a similar color. Dark-to-light color changes may require a tinted primer plus two topcoats.

Estimates are for planning purposes only. Verify quantities with your supplier and confirm code requirements with your local building department.