How much paint for a whole house interior? (1,000 to 3,000 sq ft)
A 1,500 sq ft house with 8 ft ceilings has roughly 3,166 sq ft of wall to paint, about 2.1 times the floor area once doors, windows and shared walls come off. At 407 sq ft per gallon that is 15.5 gallons for two coats, so 16 gallons of wall paint, plus 4 gallons for one coat on the ceilings and about 2 for the trim. A 2,000 sq ft house is 21 gallons of wall paint, 2,500 is 26 and 3,000 is 32; 9 ft ceilings add about 14%. The tables cover 1,000 to 3,000 sq ft at 8 and 9 ft, ceilings and trim separately, and metric homes.
Wall paint by house size, 8 ft ceilings
Wall area is 2.11 x floor area (12 x 12 room with one door and two windows, 90% for shared walls and closets). Coverage 407 sq ft per gallon per coat; the cans column is what you buy.
| House (sq ft) | Wall area (sq ft) | 1 coat (gal) | Buy | 2 coats (gal) | Buy |
|---|---|---|---|---|---|
| 1,000 | 2,111 | 5.2 | 6 | 10.4 | 11 |
| 1,250 | 2,638 | 6.5 | 7 | 13 | 13 |
| 1,500 | 3,166 | 7.8 | 8 | 15.5 | 16 |
| 1,750 | 3,694 | 9.1 | 10 | 18.1 | 19 |
| 2,000 | 4,221 | 10.4 | 11 | 20.7 | 21 |
| 2,500 | 5,277 | 13 | 13 | 25.9 | 26 |
| 3,000 | 6,332 | 15.5 | 16 | 31.1 | 32 |
Wall paint with 9 ft ceilings
| House (sq ft) | Wall area (sq ft) | 1 coat (gal) | Buy | 2 coats (gal) | Buy |
|---|---|---|---|---|---|
| 1,000 | 2,411 | 5.9 | 6 | 11.8 | 12 |
| 1,250 | 3,013 | 7.4 | 8 | 14.8 | 15 |
| 1,500 | 3,616 | 8.9 | 9 | 17.7 | 18 |
| 1,750 | 4,219 | 10.4 | 11 | 20.7 | 21 |
| 2,000 | 4,821 | 11.8 | 12 | 23.7 | 24 |
| 2,500 | 6,027 | 14.8 | 15 | 29.6 | 30 |
| 3,000 | 7,232 | 17.7 | 18 | 35.5 | 36 |
Ceilings and trim
Ceilings equal the floor area. Trim is baseboard at 5 in and casings at 3 in around the openings, scaled from the same 12 x 12 room, two coats.
| House (sq ft) | Ceilings 1 coat (gal) | Buy | Ceilings 2 coats (gal) | Buy | Trim (gal) | Buy |
|---|---|---|---|---|---|---|
| 1,000 | 2.5 | 3 | 4.9 | 5 | 1 | 1 |
| 1,250 | 3.1 | 4 | 6.1 | 7 | 1.2 | 2 |
| 1,500 | 3.7 | 4 | 7.4 | 8 | 1.4 | 2 |
| 1,750 | 4.3 | 5 | 8.6 | 9 | 1.7 | 2 |
| 2,000 | 4.9 | 5 | 9.8 | 10 | 1.9 | 2 |
| 2,500 | 6.1 | 7 | 12.3 | 13 | 2.4 | 3 |
| 3,000 | 7.4 | 8 | 14.7 | 15 | 2.9 | 3 |
How the numbers are worked out
For 1,500 sq ft at 8 ft: 1,500 x 2.11 = 3,166 sq ft of wall; x 2 coats / 407 = 15.54 gallons, rounded up to 16. The ratio comes from the 12x12 room guide; the coverage guide explains the 407 sq ft figure, and the paint calculator does any single room from its real measurements. For an open-plan house with fewer interior walls the ratio drops; for a house cut into many small rooms it rises.
Buying for a whole house
- One colour throughout: buy 5 gallon pails and box them together. A different colour per room: round each room up to whole gallons separately and expect to buy two or three cans more than the table.
- Ceiling paint is a different product (flat, non-yellowing) and a separate count; so is trim paint (semi-gloss or satin enamel).
- New drywall drinks the first coat: add primer at about the same coverage as the paint, or an extra coat on top of the tables.
- Doors are painted both sides: about 0.8 quarts per door for two coats, on top of the trim figure.
Metric: 100 to 250 m² homes
Walls at the same ratio from a 3.6 x 3.6 m room, two coats at 10 m² per litre, bought in 10 L tins; ceilings equal the floor area.
| Home | Wall area (m²) | Walls (L) | Tins | Ceilings (L) | Tins |
|---|---|---|---|---|---|
| 100 m², 2.4 m ceilings | 210 | 42 | 5 | 20 | 2 |
| 150 m², 2.4 m ceilings | 315 | 63 | 7 | 30 | 3 |
| 200 m², 2.4 m ceilings | 420 | 84.1 | 9 | 40 | 4 |
| 250 m², 2.4 m ceilings | 525 | 105.1 | 11 | 50 | 5 |
| 100 m², 2.7 m ceilings | 240 | 48 | 5 | 20 | 2 |
| 150 m², 2.7 m ceilings | 360 | 72 | 8 | 30 | 3 |
| 200 m², 2.7 m ceilings | 480 | 96.1 | 10 | 40 | 4 |
| 250 m², 2.7 m ceilings | 600 | 120.1 | 13 | 50 | 5 |
Frequently asked questions
- How many gallons of paint for a 1,500 sq ft house?
- 16 gallons of wall paint for two coats with 8 ft ceilings (3,166 sq ft of wall), 18 with 9 ft ceilings. Add 4 gallons of flat ceiling paint for one coat (8 for two) and 2 gallons of trim paint. If every room is a different colour, round each colour up separately; that is where the extra cans come from.
- How much paint for a 2,000 sq ft house interior?
- 21 gallons for the walls at two coats and 8 ft ceilings (4,221 sq ft), 24 at 9 ft; 5 gallons of ceiling paint for one coat; 2 gallons for trim. Buy the wall paint in 5 gallon pails once it is one colour throughout, and keep a quart back for touch-ups.
- How do I estimate wall area from square footage?
- A 12 x 12 ft room with 8 ft ceilings has 384 sq ft of wall, minus a door and two windows (46 sq ft), which is 2.35 times the floor. Halls and closets share walls, so this page uses 2.1 times the floor area at 8 ft and 2.4 at 9 ft. For a quote on one room, measure it; for a whole house, the ratio is within a can or two.
- How much ceiling paint for a whole house?
- Ceiling area equals floor area, so a 1,500 sq ft house is 4 gallons for one coat and 8 for two at 407 sq ft per gallon; 3,000 sq ft is 8 and 15. One coat of flat white is usual on a ceiling that is already white; two if it is stained, patched or changing colour. Vaulted ceilings are larger than the floor below them, measure those.
- Does one coat ever do for interior walls?
- Same colour over sound paint: often, and it halves the count (8 gallons instead of 16 on the 1,500 sq ft house). Any colour change, patched drywall, or a low-sheen over a gloss: two coats, and a primer under a dark-to-light change. The second coat is the cheapest part of a paint job, since the prep is already done.
- How much paint do I need per room?
- About a gallon per coat for a 10 x 10 or 12 x 12 bedroom with 8 ft ceilings, so two gallons for two coats; the 12x12 room guide has the exact figures for 8, 9 and 10 ft ceilings. This page is the sum for the whole house; when the rooms are different colours, work room by room in the paint calculator instead and round up each one.
More guides
- How much paint do I need for a 12x12 room?
Gallons of paint for a 12 x 12 ft room with 8, 9 or 10 ft ceilings, one or two coats, a door and two windows deducted, plus the 4 x 4 m room in litres.
- How many square feet does a gallon of paint cover?
A gallon covers about 350 to 400 sq ft on smooth walls, less on rough or bare surfaces. Gallons for 400 to 2,000 sq ft at one and two coats, and litres per square metre.
- How much paint do I need for a ceiling?
Quarts and gallons of ceiling paint for 10x10, 12x12, 15x15 and 20x20 ft ceilings at one and two coats, plus 3x3 to 5x5 m ceilings in litres.
- How much paint for a 10x10 room? (10x12, 12x14 and 14x16 too)
Gallons of paint for a 10x10 room with an 8 ft ceiling, a door and two windows, one or two coats, plus the ceiling; 10x12 to 14x16 rooms; 3x3 to 4x5 m rooms in litres.
Last updated 2026-09-13. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.