The Bathroom Painting Cost Calculator works out how much paint a bathroom needs and the total cost to paint it. It calculates the paintable area — walls minus tiled areas, doors and windows, plus the ceiling if you choose — then applies coats, coverage, paint price and labor.
Bathroom Painting Cost Calculator
How much paint a bathroom needs and what painting it costs — walls, ceiling, minus tiled areas, doors and windows.
Bathrooms often have large tiled areas, so subtracting tile makes a big difference to how much paint you actually need.
Formula
Paintable area = 2(L + W) × H − tile − 21 ft² × doors − 15 ft² × windows (+ L × W for the ceiling)
Paint (gal) = paintable area × coats ÷ coverage
Cost = whole gallons × price + labor
Where 21 ft² and 15 ft² are the calculator’s allowances per door and per window.
How the Calculation Works
Step 1: Wall area = perimeter × ceiling height.
Step 2: Subtract tile, doors and windows; add the ceiling if painting it.
Step 3: Multiply by coats and divide by the coverage on the paint can.
Step 4: Round up to whole gallons for cost and add labor.
Variables Explained
| Input | Meaning |
|---|---|
| Tiled / covered wall area | Tile, tub surround or panels that won’t be painted |
| Coverage per gallon | From the paint label |
| Labor | Painter’s price; 0 for DIY |
Example Calculation
Given: 8 × 5 ft bathroom, 8 ft ceiling, 40 ft² of tile, 1 door, 1 window, ceiling painted, 2 coats, 350 ft²/gal, $45/gal (example), $350 labor (example)
- Walls = 26 × 8 = 208 ft²
- Paintable = 208 − 40 − 21 − 15 + 40 = 172 ft²
- Paint = 172 × 2 ÷ 350 ≈ 0.98 gal → 1 gallon
- Cost = 1 × 45 + 350 = $395
Bathroom Paint Notes
- Bathrooms are humid; many people choose paints labeled for bathrooms or with mildew resistance and a satin or semi-gloss finish.
- Good ventilation helps paint cure and last.
- Primer, caulk and patching are separate items.
- If the ceiling uses a different paint, calculate it separately.
Frequently Asked Questions
How much paint do I need for a bathroom?
Paintable area × coats ÷ coverage. The 8 × 5 ft example above needs just under 1 gallon for two coats.
Should I subtract tile from the wall area?
Yes — only painted surfaces count.
How much does it cost to paint a bathroom?
Paint plus labor. The calculator uses your prices.
Do I need two coats?
Two coats are common, especially when changing color; follow the paint manufacturer’s advice.
Is a quart enough?
Only for very small areas; one quart covers about a quarter of a gallon’s coverage.