Paint Calculator

Professional Paint Estimation Tool

Bathroom Paint Calculator

Most bathrooms need 1 to 1.5 gallons (3 to 5 litres) of paint for two coats on the walls. Our calculator is pre-filled for a standard 8x6 bathroom — adjust the dimensions to match your room for an exact result. Free, no signup required.

Quick Answer

1 to 1.5 gallons (3 to 5 litres)

For a standard 8x6 bathroom with 8ft ceilings — two coats on walls

How Much Paint Does a Bathroom Need?

Bathrooms are the smallest rooms in most homes, which means they need less paint than any other room. A standard 8x6 bathroom has approximately 210 square feet of wall area before deducting one door and one small window. After deductions the paintable wall area is around 175 square feet. At 400 square feet per gallon with two coats, that equals about 0.9 gallons.

Most homeowners buy a single quart for very small bathrooms and 1 gallon for standard bathrooms. A large master bathroom measuring 10x12 or bigger will need 1.5 to 2 gallons for two coats. Use the calculator above and enter your exact dimensions for a precise estimate.

In litres, a standard bathroom needs 3 to 5 litres for two coats. A single 2.5 litre tin is enough for most small bathrooms. A larger bathroom needs a 5 litre tin.

Bathroom Paint Calculator — Reference Table

Bathroom Size1 Coat2 CoatsLitres (2 coats)
5x7 (small)0.35 gal0.7 gal~2.5 litres
8x6 (standard)0.45 gal0.9 gal~3.5 litres
8x10 (medium)0.6 gal1.2 gal~4.5 litres
10x12 (large)0.8 gal1.6 gal~6 litres
12x14 (master bath)0.9 gal1.8 gal~7 litres

Best Paint Finish for a Bathroom

Semi-gloss is the best finish for bathrooms. It resists moisture and humidity, wipes clean easily, and holds up to years of steam from showers and baths. Most professional painters use semi-gloss on all bathroom walls as standard practice.

Satin is an acceptable alternative if you prefer a lower sheen. Avoid flat or eggshell finishes in bathrooms — they absorb moisture, grow mildew, and peel within a year in high-humidity conditions.

Best Moisture-Resistant Bathroom Paints

Always look for paints labelled as bathroom paint, kitchen and bath paint, or paints with built-in mildewcide. Zinsser Perma-White is the top choice for problem bathrooms — guaranteed against mould for 5 years. Behr Premium Plus Kitchen & Bath at around $34 per gallon is a reliable mid-range option. Sherwin-Williams Emerald Bath at around $92 per gallon is the premium long-lasting choice.

Tips for Painting a Bathroom

Ventilate during and after painting. Run the exhaust fan during painting and for 24 hours after. Good ventilation is critical for paint adhesion in humid bathrooms.

Clean walls thoroughly first. Wipe down with TSP cleaner or sugar soap. Paint will not adhere properly to soap scum or mildew.

Use semi-gloss — not eggshell. The most common bathroom painting mistake. Eggshell looks fine initially but peels within 12 months in a shower bathroom.

Caulk before painting. Re-caulk around the bath, shower, and sink before painting. Fresh paint over cracked caulk looks immediately unfinished.

Wait 48 hours before using the shower. Paint feels dry in 2 hours but needs 48 hours to fully cure before steam exposure.

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Frequently Asked Questions

How much paint do I need for a bathroom?

Most bathrooms need 1 to 1.5 gallons for two coats on the walls. A standard 8x6 bathroom needs about 0.9 gallons. Use the calculator above and enter your exact dimensions for a precise estimate.

What paint finish is best for a bathroom?

Semi-gloss is the best finish for bathrooms. It resists moisture and humidity, wipes clean easily, and prevents mildew growth. Avoid flat or eggshell finishes — they peel in high-humidity bathrooms.

Do I need special bathroom paint?

Yes — use a paint labelled for bathrooms or kitchens, or any paint with built-in mildewcide. Zinsser Perma-White, Behr Kitchen & Bath, and Sherwin-Williams Emerald Bath are all good choices.

How many litres of paint for a bathroom?

A standard bathroom needs 3 to 5 litres for two coats. A small bathroom can be done with a 2.5 litre tin. A larger bathroom needs a 5 litre tin.

How long does bathroom paint take to dry?

Bathroom paint feels dry in 1 to 2 hours. Wait 4 hours before a second coat. Wait 24 to 48 hours before using the shower to allow the paint to fully cure.

Should I paint the bathroom ceiling the same colour as the walls?

In small bathrooms, matching ceiling and walls makes the space feel larger. In larger bathrooms a white ceiling is more common. Always use moisture-resistant paint on bathroom ceilings.