How Many Gallons of Paint for a 12x12 Room?
Estimate paint gallons for a 12x12 room by wall height, coats, openings, paint coverage, and waste allowance.
Last updated: May 2026
Who this guide is for
This guide answers a common paint-planning question for a standard bedroom, office, or small living space.
What to compare
A 12x12 room can still vary because wall height, door and window area, number of coats, primer, and color change all affect gallons.
Buying guidance
Run the paint coverage calculator with your actual wall height and coverage per gallon, then buy enough for the planned coats plus touch-ups.
Use the calculator first
Start with the related calculator, then use this guide to interpret the result. Sizes, costs, capacities, and product ratings should always be checked against current labels, reviews, and your actual room or aquarium setup.