Planning result
With 8 foot walls, one standard door, two standard windows, two coats, and 10% waste, this room needs about 2.1 gallons at 400 sq ft per gallon. Most shoppers would round up to 3 gallons or adjust after checking the paint label.
Assumptions
| Room size | 12 ft by 14 ft with 8 ft walls. |
|---|---|
| Openings | One 21 sq ft door and two 12 sq ft windows. |
| Coats and waste | Two finish coats plus 10% waste. |
| Coverage | 400 sq ft per gallon per coat for planning. |
Calculation
| Step | Result | Formula |
|---|---|---|
| Wall area | 416 sq ft | 2 x (12 + 14) x 8 |
| Openings | 45 sq ft | 21 + 12 + 12 |
| Paintable wall area | 371 sq ft | 416 - 45 |
| Two-coat area | 742 sq ft | 371 x 2 |
| Waste-adjusted area | 816 sq ft | 742 x 1.10 |
| Estimated paint | 2.04 gallons | 816 / 400 |
Why this estimate rounds up
Paint is sold in fixed container sizes, and label coverage may be lower on textured, patched, or porous walls. Rounding up helps avoid running out before the last wall is finished.
When the number changes
Add ceiling paint, trim paint, primer, closets, extra windows, or a lower coverage rate separately. A strong color change can also require primer or more careful coat planning.
Next step
Use the linked calculator or planning hub to adjust dimensions, waste, coverage, depth, spacing, or product packaging for the real project.
Related guides
FAQ
Is 2 gallons enough for a 12x14 room?
It may be close at high label coverage, but 3 gallons is safer for two coats, waste, and touch-ups.
Does this include the ceiling?
No. A 12x14 ceiling adds 168 square feet per coat.
Should doors and windows always be subtracted?
Subtracting large openings improves the estimate, but waste may offset small openings.