Paint & Finishes Calculators
Calculate paint coverage, gallons needed, and finishing material requirements.
A fresh coat of paint is one of the most cost-effective ways to transform a room. But buying too much paint wastes money, while running short mid-project means mismatched colors and frustrating delays. Our paint calculators help you order exactly the right amount. Paint coverage varies by surface texture, paint quality, and color change. A gallon of quality paint typically covers 350-400 square feet on smooth surfaces. Dark-to-light color changes often require additional coats, while primer helps reduce the number of finish coats needed. Our calculators account for doors and windows (which reduce painted area) and help you plan for multiple coats. We also factor in paint type since flat, eggshell, semi-gloss, and high-gloss paints have slightly different coverage rates.
Available Calculators
Frequently Asked Questions
How much paint do I need for one coat?
One gallon covers approximately 350-400 square feet. For a 12x12 room with 8-foot ceilings, you need about 1.5 gallons per coat for walls only, or about 2 gallons including the ceiling.
Do I need primer before painting?
Use primer on new drywall, when covering dark colors with light ones, over stains, or on previously unpainted surfaces. Modern paint-and-primer combinations work for basic color changes.
How many coats of paint do I need?
Most projects need two coats for even coverage and color depth. Light-over-dark may need three coats. High-quality paints often cover better and may require fewer coats.