Bathroom paint calculator

A typical bathroom needs about 1 gallon

Based on a standard 8 × 6 ft bathroom with 8-ft ceilings, the walls work out to about 188 sq ft after subtracting 1 door and 1 window. A standard two-coat repaint needs roughly 1 gallon of quality interior paint. The recommended finish for a bathroom is satin — more on why below.

Choose Satin Or Semi-Gloss, Never Flat

Flat paint is porous — it drinks up steam, holds moisture, and grows spots and mildew within months in a bathroom. Satin gives enough sheen to shed water and wipe clean while still looking like wall paint. Semi-gloss is even more washable and is the smart pick for a bathroom with poor ventilation or no exhaust fan, though it shows wall imperfections more, so prep the surface smooth before you commit to that much shine.

Fix Ventilation And Mildew Before You Paint

Paint cannot solve a moisture problem, it only hides it briefly. If there is existing mildew, kill it and clean the surface before priming — paint over live mildew and it bleeds back through. Run the exhaust fan or crack a window, and look for a mildew-resistant additive or a paint formulated for kitchens and baths. A room that stays damp for hours after a shower needs the fan fixed first or any finish will fail early.

Always Paint The Bathroom Ceiling

The ceiling takes the most steam of any surface in the house and discolors faster than the walls — skip it and it yellows into a visible halo above the shower within a year or two. Use the same satin or semi-gloss you put on the walls so it sheds moisture, or a dedicated mildew-resistant ceiling paint. One can usually covers both walls and ceiling here, since the room is small.

How the bathroom paint math works

Wall area is perimeter × ceiling height: (2 × 8 + 2 × 6) = 28 ft of perimeter, times a 8-ft ceiling, equals 224 sq ft of gross wall. We subtract 21 sq ft per door and 15 sq ft per window, leaving about 188 sq ft of paintable wall. Multiply by the number of coats, divide by a coverage rate of about 388 sq ft per gallon, and round up to the nearest quart — that is the number you take to the store. Change any input in the calculator above and it recalculates instantly.

Paint needed by coats

Two coats is the right default for almost every repaint. Use one coat only for a same-color refresh, and three for dark-over-light changes or vivid colors that cannot hide in two. The ceiling adds 48 sq ft (length × width) when you choose to paint it — usually a separate flat-white product, so most people buy a dedicated gallon for it.

What it costs to paint a bathroom

Doing it yourself, the paint for two coats runs about $40–$70 (roughly 1 gal at $40–$70 a gallon), plus $50–$100 in supplies — rollers, brushes, tape, trays, and a drop cloth. That is your whole cost if you bring the labor.

Hiring a painter changes the math: most pros charge $2–$5 per square foot of floor area, so a 48 sq ft bathroom lands around $96–$240. Labor is 75–95% of an interior bill because prep, cutting in, and cleanup eat the hours. For a full paint-plus-labor breakdown, use the paint cost calculator.

Paint cost by brand

Coverage is similar (about 350–400 sq ft per gallon) across the major interior lines, so the price tier is what moves your bill. These are current per-gallon prices for the brands the calculator can price for you — pick one in the result panel above and it multiplies your gallons for this bathroom into an exact paint cost:

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