How much paint a wall area needs, and what it costs.
Paint needed
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Estimated cost
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Total area to cover
Coverage rates vary by paint brand, wall texture and application method — check the actual coverage figure on your paint can for a precise number.
How this works
Paint needed = (Wall area × number of coats) ÷ coverage per gallon or litre
Most paint cans state their own coverage rate — use it instead of the default here for an accurate result.
Two coats is standard for a colour change or new drywall; one coat can be enough for a close-match repaint on a sound existing coat.
Round up to the next full can — paint does not sell in the exact fraction the maths gives you.
Currency
Amounts follow the currency selected above.
How much wall area does one gallon of paint cover?
Roughly 350-400 square feet per coat for a smooth wall with standard latex paint, though it varies by brand, sheen and surface texture — always check the can.
Do I need to subtract doors and windows?
For a precise figure yes — subtract their area from the total wall area before entering it here. For a quick estimate, most people skip this and treat it as a small safety margin instead.
Should I round up the number of gallons?
Yes — always round up to the next full can. Running short mid-job means a delay waiting for more, and colour can vary slightly between batches.
How many gallons of paint do I need for a room?
Enter the total wall area and how many coats you plan above — the calculator divides by your paint's coverage rate (about 350-400 sq ft per gallon per coat) and rounds up to a full can, so you get an exact gallon count for that room rather than a rule of thumb.