Calculate how much primer you need before painting, adjusting for how absorbent the surface is.
Primer Needed
— gallons
For full coverage.Usage Tip
A tinted primer close to your topcoat color can cut the number of finish coats you need on a big color change.
THE MATH
adjusted area = surface area × absorbency multiplier
gallons = adjusted area ÷ coverage rate
gallons = adjusted area ÷ coverage rate
Primer coverage drops on thirsty surfaces. The effective area is the real area times an absorbency multiplier, and gallons follow from the coverage rate on the label.
Enter the surface area, the primer coverage rate, and how absorbent the surface is.
Bare drywall and raw wood soak up more, so they use a higher multiplier.
Bare drywall and raw wood soak up more, so they use a higher multiplier.