Paint & Stain Calculator
How many gallons a job takes, with primer if the surface is bare, and the temperature window plus the best stretch of the year to paint or stain it where you live.
Set your place for the painting season and temperature window.
Coverage and the temperature window
A gallon of exterior paint covers roughly 350 to 400 square feet on a smooth wall in one coat, less on rough or porous surfaces, and primer covers about 250. Most exterior coatings are rated for application between about 50 and 90 degrees Fahrenheit (10 to 32 Celsius) for both the air and the surface, on a dry day with no rain in the forecast for 24 hours. Paint in the shade, not on a wall in direct sun, and stop early enough that the surface is dry before evening dew.
Coverage figures follow major-manufacturer guidance and vary by product, color, and surface. Always read the can label and data sheet, which govern.