How to use this calculator
- Enter each rectangular surface area to be primed.
- Add all separate surfaces.
- Choose the number of primer coats.
- Enter coverage from the selected primer and calculate gallons and liters.
How the calculation works
Measured surface areas are combined, multiplied by the entered coat count, and divided by the editable primer coverage rate.
Formula
Total area = Σ(length × width) Coated area = total area × primer coats Gallons = coated area ÷ entered coverage
Worked example
A total surface area of 500 square feet with one primer coat at an entered 300 square feet per gallon requires about 1.67 gallons, or 6.31 liters.
Project considerations
- Primer coverage varies by product and surface; verify the label.
- The displayed default is an editable example rather than a universal rate.
- Spot priming, stain blocking, porous surfaces, and specialized primers may require separate planning.
Frequently asked questions
What coverage rate should I use?
Use the coverage stated for the selected primer and the project’s surface conditions.
Can I calculate two primer coats?
Yes. Enter the required coat count and the calculator multiplies the measured area accordingly.