How to use the anti-corrosion paint quantity calculator
Protective coating systems build up a specified total dry film thickness (DFT) by applying a primer, an intermediate coat and a topcoat a set number of times. Enter the area to be painted along with the DFT per coat, number of coats and volume solids for each layer, and this tool returns the theoretical coverage and the gallons you actually need to order.
Theoretical coverage in square feet per gallon is 1,604 multiplied by the volume solids fraction and divided by the DFT in mils. A 65% volume solids epoxy primer applied at 3 mils therefore covers roughly 348 sq ft per gallon, and adding the loss factor gives the practical order quantity.
Loss depends heavily on application method and geometry: 10 to 20 percent for brush and roller, 20 to 40 percent for airless spray, and the upper end for open steel framing or windy sites. Treat the output as a takeoff estimate and confirm the manufacturer technical data sheet coverage and the specified DFT before placing an order.
Frequently asked questions
Theoretical coverage in square feet per gallon equals 1,604 multiplied by volume solids, divided by the target dry film thickness in mils. A 65% solids coating applied at 3 mils covers about 348 sq ft per gallon.
Brush and roller application typically loses 10 to 20 percent, while airless spray loses 20 to 40 percent. Use the higher end for open steel framing or windy outdoor conditions.