Primer and Paint Calculator Combo
Primer and paint calculator combo — estimate primer and top coat together in one free tool.
Runs entirely in your browser — room sizes and coverage figures never leave this pageTry: Room length=12, Room width=12, Wall height=8, Number of doors=2, Number of windows=2, Top-coat coverage=350, Top-coat coats=2, Waste factor=15, Surface condition=newDrywall, Color change=none → 312 sq ft, 3 gallons, 25.63 gal, 26 gallons
How to use
This calculator plans the whole job: primer seals the surface, top coats do the finish. It estimates primer from the net wall area (250 sq ft/gal), adds an extra coat for color changes, and increases primer on new drywall.
FAQ
Why calculate primer separately?
Primer covers around 250 sq ft per gallon — less than top-coat paint — because it seals porous surfaces and improves adhesion. Counting it separately keeps the estimate accurate.
Which primer should I choose?
PVA primer for drywall, shellac-based for stains, bonding primer for glossy surfaces, and exterior-specific primer outside. Ask your paint store for the right match.