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Paint Calculator

Figure out how many gallons a paint job really needs. Add each room, subtract doors and windows, pick one or two coats, and get a printable takeoff sheet — your measurements never leave this page.

This tool does the gallon math — InvoiceStream Pro turns it into a priced estimate, gets it signed, and collects the payment.

Turn your paint takeoff into a professional estimate your customer signs on the spot — InvoiceStream Pro, free to start →

Rooms

Wall area: 0 SF

Standard deductions

standard 3'×7' door
standard 3'×5' window

Paint

Typical label coverage — check your paint can.

Takeoff sheet

Paint Takeoff
Wall paint estimate
Date:
RoomSize (ft)Doors / WindowsWall SF
Room 11 / 10
Total wall area0 SF
Coats2
Coverage per gallon350 SF
Deductions (door / window)21 / 15 SF
Gallons to buy0 gallons

about 0.0 — buy 0 gallons

Planning estimate — surfaces, texture, and color changes affect real coverage.

Frequently asked questions

How much wall area does a gallon of paint cover?

Most paint labels quote around 350 square feet per gallon, per coat, and that is a reasonable planning number. Real coverage is usually lower on textured, porous, or previously unpainted surfaces, so check the label on your specific paint and round up when in doubt.

Do I need two coats of paint?

Usually, yes — two coats are the norm for color changes, deeper colors, and even coverage. A single coat can work when you are repainting in the same or a very similar color. Primer is a separate product: bare drywall, stains, and dramatic color changes often call for a primer coat before the paint.

How do I measure walls for paint?

Measure the room's width and length, add them together and double it to get the perimeter, then multiply by the ceiling height for gross wall area. Subtract openings you will not paint — a standard 3'×7' door is about 21 square feet and a standard 3'×5' window is about 15. This calculator does that math for every room automatically.

How do I turn this into a quote my customer can sign?

This free calculator gives you the material takeoff. Turning it into a priced, professional estimate your customer can e-sign and pay is what InvoiceStream Pro does — you can start there for free.