What it calculates
Estimate primer gallons from surface area and coverage.
Primer Coverage Calculator
Estimate primer gallons from surface area, coats and product coverage.
Planning and estimating aid only. Verify project requirements, manufacturer instructions, adopted codes, permits, and field conditions before performing regulated work.
Painting estimating
How to Use This Calculator
Enter the measurements and job information you know, select Calculate, then use the result as a starting point for estimating, purchasing or project planning.
How the calculation works
Surface area × primer coats ÷ coverage per gallon, with the entered waste allowance added.
What the result means
New drywall, masonry, stains and porous surfaces can change actual primer consumption.
Use real project measurements
Start with the actual field dimensions or equipment values from the job. Run the calculator once with your measured quantity, then test a second scenario with your normal waste, routing or safety allowance. This makes the tool useful for both the takeoff and the customer estimate.
Contractor tip: Save the measurements that produced your estimate in the job notes so the quantity can be checked later if the scope changes.
Verify the final quantity
Coverage varies with surface texture, porosity, color change, application method and product. Use the coating manufacturer's stated spread rate for final purchasing.
Good practice: Compare the calculated quantity with plans, specifications, product packaging and current field conditions before purchasing material.