Paint Calculator for a Bedroom
Estimate gallons of paint for any bedroom.
Use this free paint calculator to estimate how many gallons of paint you need for a room. Enter the room length, width, ceiling height, number of doors and windows, and number of coats. The calculator subtracts door and window areas and uses 350 ft² of coverage per gallon.
Gallons
1.81
Buy the next whole gallon
Paintable area
316 ft²
Total wall area
352 ft²
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How does the paint calculator work?
Wall area is the room perimeter × ceiling height. Subtract roughly 21 ft² per door and 15 ft² per average window, then multiply by the number of coats and divide by 350 ft²/gallon.
Formula: gallons = ((2(L+W) × H − doors×21 − windows×15) × coats) ÷ 350
What else do people ask about this calculator?
How many gallons of paint for a 12x12 bedroom?
A 12×12 ft bedroom with 8 ft ceilings has about 384 sq ft of wall (minus doors and windows). That's 1 gallon for a single coat, or 2 gallons for two coats on a color change.
Do I need primer in a bedroom?
Prime if the walls are bare drywall, patched, stained or a very different color from your new paint. Paint-and-primer-in-one still needs a separate primer coat over raw drywall or repairs.
How much paint do I need for a 12×12 room?
A 12×12 room with 8 ft ceilings, 1 door and 1 window needs about 2 gallons for two coats.
How much does a gallon of paint cover?
About 350 ft² per gallon on smooth interior walls. Textured or porous surfaces reduce coverage to 250–300 ft².
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Where can I learn more about these materials?
Weights, coverage, types and buying tips for the materials this calculator estimates.
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