How this calculator works
This runs our paint calculator and caulk calculator on one room. The walls are the perimeter times the ceiling height less the doors and windows, the ceiling is length times width, and each is multiplied by the coats and divided by the coverage of a gallon. Tape and caulk follow the lengths of the ceiling line, baseboards and trim around the openings.
Worked example: a 14 × 12 ft room with 8 ft ceilings, one door and two windows needs 2.09 gallons for the walls with two coats at 350 ft² a gallon, 0.96 gallons for the ceiling, 1.04 gallons of primer for one coat, 153 ft of tape and 2 tubes of caulk.
Paint for common room sizes (8 ft ceilings, 1 door, 2 windows, 2 coats, 350 ft² a gallon)
Gallons of wall and ceiling paint, and rolls of 60 yd painter's tape.
| Room | Wall paint | Ceiling paint | Tape rolls |
|---|---|---|---|
| 10 × 12 ft | 1.72 gal | 0.69 gal | 1 |
| 12 × 12 ft | 1.90 gal | 0.82 gal | 1 |
| 14 × 12 ft | 2.09 gal | 0.96 gal | 1 |
| 14 × 16 ft | 2.45 gal | 1.28 gal | 1 |
| 16 × 20 ft | 3.00 gal | 1.83 gal | 2 |
Tips before you buy
- Buy all the paint for the room at once and mix the cans together (boxing), so that the color is the same on every wall.
- Keep a little left over for touch-ups, labeled with the room and the date.
- For a dramatic color change, a tinted primer can save a third coat.
- Rough or textured walls use up to 20 to 30% more paint: choose a lower coverage figure.
- Paint the ceiling first, then cut in the edges of the walls with a brush before you roll each wall.
Tools & materials for this project
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Frequently asked questions
How much paint do I need for a 12x14 room?
About 2.09 gallons for the walls with two coats, plus 0.96 gallons if you paint the ceiling. This assumes 8 ft ceilings, one door, two windows and 350 ft² per gallon.
Do I need primer before painting?
On bare patches, stains, new drywall and big color changes, yes. A coat of primer over these walls is about 1.04 gallons. Primer is cheaper than extra coats of finish paint.
How many rolls of painter's tape do I need for a bedroom?
One roll of 60 yard (180 ft) tape is enough for most bedrooms: this one needs about 153 ft for the ceiling line, the baseboards and the door and window trim.
How much paint is needed for the walls alone?
2.09 gallons for two coats. The ceiling adds 0.96 gallons.
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Related calculators & guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.