HomeMeasure Pro

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How Much Paint Do You Need? Find Out in Seconds.

Free home improvement calculators and guides for US homeowners and DIYers. Figure out exactly how much paint, flooring, tile, concrete, fencing, mulch, wallpaper, and drywall you need — no guesswork, no wasted material. Enter your room below — get exact gallons, liters, and cost instantly.

How do you want to measure?
Coats of paint
Paint finish (coverage per gallon)
10%

10% is a safe default — covers spills, roller absorption, and future touch-ups.

Your paint estimate

Buy this much

2 gals

1.95 gal · 7.4 L exact

Wall area
384 sq ft
Minus doors & windows
−51 sq ft
Paintable area × 2 coats
666 sq ft
With 10% waste
733 sq ft

Rounded up to the nearest quart — paint is sold in gallons and quarts, so you never come up short mid-wall.

Open the full paint calculator page →

Home Improvement Calculators

Twelve pro-grade DIY calculators — paint, wallpaper, flooring, vinyl plank cost, tile, concrete, fencing, mulch, and drywall. All free, all instant.

Paint Calculator

Gallons, liters & cost for any room.

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Wallpaper Calculator

Rolls needed for any wall.

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Flooring Calculator

Sq ft, boxes & waste for laminate, vinyl & hardwood.

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Tile Calculator

Tiles, thinset & grout for floors and backsplashes.

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Concrete Calculator

Bags or cubic yards for slabs & footings.

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Fence Calculator

Pickets, posts & rails for any run.

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Mulch Calculator

Cubic yards for beds & gardens.

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Drywall Calculator

Sheets, screws & joint compound.

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Vinyl Plank Cost Calculator

Installed LVP cost, DIY vs pro.

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Concrete Pad Cost Calculator

Pad cost, cubic yards, ready-mix vs bags.

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Tile Square Footage Calculator

Area, waste by pattern & boxes to buy.

Use it free →

Fence Post Depth Calculator

Burial depth by frost line & fence height.

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Why HomeMeasure Pro?

Pro-grade formulas

Our math follows the same method professional painters use: true wall area, minus doors and windows, times coats, plus a realistic waste allowance — not a rough guess.

Built for US homes

Feet, gallons, quarts, and dollars — plus liter conversions for imported paints. No metric-only tools, no confusing units.

Fast & free forever

Instant results as you type, mobile-friendly, no account, no paywall. Supported by ads so the calculators stay free.

Frequently Asked Questions

How much paint do I need for a 12x12 room?
A 12×12 ft bedroom with 8 ft ceilings has about 384 sq ft of wall. After subtracting one door and two windows and painting two coats, you'll need roughly 2 gallons of paint (including 10% for waste). Use the calculator above for your exact room.
How many square feet does a gallon of paint cover?
Most interior paints cover 350–400 sq ft per gallon. Flat/matte finishes cover the most (around 400 sq ft), while satin and semi-gloss cover closer to 350 sq ft because they go on thicker. Always check your specific can — coverage varies by brand.
Is one coat of paint enough?
One coat works when repainting the same or a very similar color over a previously painted wall in good condition. You'll need two coats when changing colors dramatically, painting over bare drywall, or covering stains. When in doubt, budget for two.
Should I include doors and windows in my calculation?
No — subtract about 21 sq ft per standard door and 15 sq ft per average window. Our calculator does this automatically when you enter the counts.
How much extra paint should I buy for waste?
10% is the safe standard. It covers roller absorption, small spills, cutting-in overlap, and leaves you paint for future touch-ups. For textured walls, consider 15%.
Is this paint calculator really free?
Yes — every calculator on HomeMeasure Pro is free with no signup and no limits. We keep the lights on with ads, so the tools stay free forever.