Paint Cost Calculator
How much will the paint actually cost? Enter the room and the price on the can — the result is the bill at the till, not a vague range.
How the cost is calculated
- Wall area = 2 × (length + width) × height, minus 21 sq ft per door and 15 sq ft per window.
- Gallons = wall area × coats ÷ 350 sq ft per gallon, rounded up.
- Cost = gallons × your price per gallon.
Worked example
A 12 × 14 ft bedroom, 8 ft ceilings, two doors, two windows, two coats, paint at $45 per gallon:
- 416 − 42 − 30 = 344 sq ft of wall
- 344 × 2 = 688 sq ft ÷ 350 = 1.97 → 2 gallons
- 2 × $45 = $90 in paint
Add roughly $40–80 for a roller, tray, tape and drop cloths, and the whole DIY job lands near $150.
What paint costs
| Tier | Per gallon | Coverage | Best for |
|---|---|---|---|
| Builder grade | $20–30 | ~300 sq ft | Rentals, closets, quick turnover |
| Mid range | $35–50 | ~350 sq ft | Most interior rooms |
| Premium | $55–80 | ~400 sq ft | High-traffic rooms, deep colours |
| Primer | $20–35 | ~350 sq ft | Bare drywall, patches, dark to light |
DIY or hire a painter?
| Scope | DIY | Hired |
|---|---|---|
| Single bedroom | $120–180 | $300–800 |
| Whole house interior | $800–1,500 | $3,000–8,000 |
| Exterior, single storey | $600–1,200 | $2,500–6,000 |
Painter quotes usually include prep, masking and cleanup. Ask whether they charge per room, per square foot of wall, or by the hour — the three produce very different numbers on the same job.
Frequently asked questions
How much does it cost to paint a room?
A 12 × 14 bedroom needs about 2 gallons at two coats, so $80–140 in paint depending on the tier, plus $40–80 in supplies. A professional painter typically charges $300–800 for the same room including prep.
How much paint do I need per room?
Roughly 2 gallons for a standard bedroom at two coats. The calculator subtracts doors and windows, which is worth about half a gallon in a typical room, so do not skip that step.
Is expensive paint worth it?
Above the cheapest tier, usually yes. Better paint covers in fewer coats and resists scrubbing, so the cost per finished square foot is often lower even though the can costs more.
Should I add primer to the cost?
Add one coat of primer over bare drywall, fresh patches, bare wood, or any wall going from dark to light. On already-painted walls in a similar colour, a paint-and-primer product is enough and the calculator's two-coat figure holds.