How to Calculate Paint Coverage

By Bill Brown ; Updated September 15, 2017

Things Needed

  • Scraper
  • Primer (appropriate to the surface)
  • Paint
  • Roller, handle, sleeve and tray
  • Tape measure
  • Measuring cup
For unfamiliar surfaces, a test is the best way to calculate coverage.

Most paints for general consumer use cover about 400 square feet per gallon. This amount is maximum coverage on a well prepared surface with no heavy texture or other abnormalities. If you are facing a stucco or other kind of unfamiliar surface, and it’s a big job, the best way to calculate the coverage of the paint is to do a test.

Remove all loose debris and properly prime the surface to get the maximum coverage out of your paint.

Measure out 16 ounces of your selected paint and put it in the roller tray.

Apply the paint to your prepared and primed surface using the roller. A thick napped roller may be required for surfaces with a lot of texture. Try to keep the application rectangular so it will be easier to measure.

Measure the length and width of the area covered by the paint.

Multiply the length by the width to get the paint coverage. For example, if you were able to cover a rectangle 5 feet by 6 feet, that equals 30 square feet.

Multiply your coverage from step 4 by eight to get your paint coverage for one gallon of paint. Once the paint is dry, you should also be able to assess whether or not you will need a second (or potentially third) coat for full coverage.

About the Author

Bill Brown has been a freelance writer for more than 14 years. Focusing on trade journals covering construction and home topics, his work appears in online and print publications. Brown holds a Master of Arts in liberal arts from St. John's University and is currently based in Houston.