Living Room Paint Calculator
Estimate paint for a larger living room with tall walls, several windows, and two coats.
Calculator
Free, runs entirely in your browser, and your numbers never leave your device. Results are estimates for planning only.
What this calculator does
Living rooms are large, often with 9-foot walls and several windows, so the paint adds up quickly. This tool estimates the gallons for a spacious room, subtracts the doors and windows, and applies two coats so your order matches the job.
How to use it
- Enter the room length and width and the wall height (9 ft is common in newer homes).
- Count the doorways and the windows, including any sliding doors.
- Keep two coats and use the coverage from your paint can.
- Read the gallons and round up to whole cans.
The formula
Paintable = 2 × (length + width) × height − openings. Paint = paintable × coats × (1 + waste%) ÷ coverage.
Example calculation
A 16 ft × 20 ft living room with 9 ft walls, two doorways, three windows, two coats at 350 sq ft/gal:
- Wall area: 2 × (16 + 20) × 9 = 648 sq ft
- Openings: 2 × 21 + 3 × 15 = 87 sq ft
- Paintable: 648 − 87 = 561 sq ft
- Two coats: 1,122 sq ft, +10% waste ≈ 1,234 sq ft
- Paint: 1,234 ÷ 350 ≈ 3.5 gallons
Result: About 3.5 gallons — buy 4 gallons (a 5-gallon pail can be cheaper for big rooms).
Buying and planning tips
- For a large open room, a 5-gallon pail often costs less per gallon than four singles.
- Box your paint (mix all cans together) so the color is uniform across big walls.
- An accent wall in a second color? Estimate it separately so you do not over-order the main color.
Common mistakes to avoid
- Assuming 8 ft walls when newer living rooms are often 9 or 10 ft.
- Buying single gallons when a pail would be cheaper and more consistent.
- Overlooking a sliding patio door, which is a large opening to subtract.
Assumptions and limits
- Each door is treated as 21 sq ft and each window as 15 sq ft; a wide patio door is closer to two openings.
- Coverage of ~350 sq ft per gallon is approximate.
- Finish paint only — bare or repaired walls may need primer first.
Frequently asked questions
How much paint do I need for a living room?
A large 16×20 ft living room with 9 ft walls needs about 3 to 4 gallons for two coats after subtracting doors and windows.
Is a 5-gallon pail better than gallons?
For big rooms, a pail is usually cheaper per gallon and guarantees one consistent color, with no can-to-can variation.
How do I handle an accent wall?
Estimate the accent wall on its own (its width × height, minus any openings) so you buy the right amount of each color.
Do taller walls really change the total much?
Yes. Going from 8 ft to 9 ft walls adds about 12% to the wall area, which can be a whole extra gallon in a large room.
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