Paint Coverage Calculator: Gallons You Need | FloorCrafted
Paint Coverage Calculator
Enter your walls, doors, windows and coats — get the exact gallons of paint (and primer) to buy.
Your paint estimate
– gallons
of paint to buy
Buy all your paint at once — tint varies between batches.
Frequently asked questions
One coat or two?
Two coats is the safe default. Most coverage ratings, like 350 sq ft per gallon, assume two coats for full, even color. One coat only works over a very similar color on a well-primed surface.
Do I need primer?
Use primer on bare drywall, patched spots, dark-to-light color changes, or stained surfaces. Check the primer box in the calculator and it adds primer gallons at 300 sq ft per gallon.
How much does a door or window deduct?
A standard interior door deducts 21 sq ft (3 by 7 ft) and an average window deducts 15 sq ft. The calculator subtracts them automatically based on your counts.
Can I share this result?
Yes — use the Share button above to send your paint estimate, or Copy results to paste it into a note or shopping list.