Paint Calculator

Paint coverage is estimated by calculating the total wall area, subtracting doors and windows, and multiplying by the number of coats. This total square footage is then divided by the coverage rate per gallon (typically 350 sq ft) to find the required volume.

One gallon of paint typically covers between 300 and 400 square feet, though this calculator defaults to a standard estimate of 350 square feet. Coverage can vary depending on surface texture, porosity, and color changes.

You generally need two coats of paint for a professional, durable finish and proper color saturation. One coat may suffice when refreshing an identical color on a clean, primed wall, while three coats might be needed for extreme color transitions.

Yes, you should subtract doors and windows to avoid overbuying paint. The standard deduction is 20 square feet per average door and 15 square feet per average window.

You will need approximately 2 to 3 gallons of paint for a standard 12x12 room with 9-foot ceilings and two coats. This estimate assumes a gross wall area of 432 square feet and accounts for normal deductions like one door and two windows.

No, primer is not included in paint coverage estimates as it is a separate product applied before painting. Primer seals porous surfaces and ensures paint adheres properly, meaning you will need to buy primer separately if painting raw drywall or making a major color change.

You will need about 1 gallon of flat ceiling paint for every 350 square feet of ceiling area. To calculate your ceiling's square footage, multiply the room's length by its width.

Yes, you should purchase about 10% more paint than estimated to account for touch-ups, spills, and future repairs. Buying one extra quart or gallon ensures you have paint from the same color-matched batch for any necessary fixes.

Textured walls can reduce paint coverage by up to 20% to 25% because the uneven surface has more actual area than a flat plane. If you have stucco, brick, or heavy plaster walls, you should lower your estimated coverage per gallon to 250–300 square feet.

Yes, the color change determines whether you will need extra coats or a tinted primer. Moving from a dark wall color to a light one typically requires a primer coat plus two coats of paint to prevent show-through.

You can use the same paint color, but you should typically use a different gloss level (sheen) such as semi-gloss or gloss for trim and baseboards. Trim paint is formulated to be more durable and easier to clean than standard wall paint.

Opened paint can last up to 10 years if stored in a cool, dry place in an airtight container. Be sure to seal the lid tightly and avoid storing paint where temperatures drop below freezing, which ruins the emulsion.