Paint Coverage
Gallons per coat by surface porosity and coats.
Example
You enter
- Area (ft²) 700
- Coats 2
- Primer needed true
- Surface porosity smooth
You get
- Gallons per coat 2
- Total paint 4 gal
- Primer 2 gal
No published worked example is on file for this calculation. It is checked against a hand-worked derivation of its method and an independent reference test.
Details, formula, and sources
Formula or tableGallons per coat = area / coverage for the surface (smooth 350, textured 250, rough 175 ft²/gal); total = per coat × coats; primer = one coat. No separate waste factor.
Source and editionManufacturer technical data sheets (PDS) by name.
Free accessFree at each manufacturer site (sherwin-williams.com, benjaminmoore.com, behr.com).
What governsEstimate. AHJ and licensed professional govern.
API field namesarea_ft2, coats, primer_needed, surface_porosity, gallons_per_coat, total_paint_gallons, primer_gallons
- Coverage by surface smooth 350 / textured 250 / rough 175 ft²/gal (manufacturer PDS ranges); the table carries the surface penalty, applied oncemanufacturer PDS typical