Room Paint Calculator
Calculate exactly how much paint you need for an entire room. We account for walls, doors, windows, and even the ceiling. Stop guessing and buying too much (or too little) paint.
Planning a Room Painting Project
Painting an entire room transforms the space, but the logistics can be tricky. Accurate measurement prevents the frustration of running out of paint mid-wall or storing 3 extra gallons forever.
Step-by-Step Calculation Guide
- Measure Perimeter: Add length + width + length + width. (e.g., 12+12+12+12 = 48 ft).
- Calculate Surface Area: Multiply perimeter by height. (48 × 9 = 432 sq ft).
- Subtract Openings: Don't pay to paint doors/windows! Subtract ~21 sq ft per door and ~15 sq ft per window.
- Divide by Coverage: Standard gallon covers 350 sq ft. (400 sq ft / 350 = 1.14 gallons).
- Multiply by Coats: Always plan for 2 coats for rich color. (1.14 × 2 = 2.28 gallons).
Paint Types Explained
- Ceiling Paint: Flat finish to hide imperfections. Usually white. Spatter-resistant.
- Wall Paint (Living/Bedroom): Eggshell or Satin. Low sheen, easy to wipe down.
- Kitchen/Bath: Semi-gloss. High durability against moisture and scrubbing.
- Trim/Doors: Semi-gloss or High-gloss. Stands up to fingerprints and scuffs.
Professional Tips
Always "box" your paint if you need more than one gallon. This means researching mixing all gallons together in a 5-gallon bucket before starting. This ensures color consistency, as slight variations exist between manufacturing batches.
Frequently Asked Questions
How much paint do I need for a 12x12 room?
For a standard 12x12 room with 8ft ceilings, you have roughly 384 sq ft of wall area. With 2 coats, you'll need just over 2 gallons of wall paint and about 0.5 gallons of ceiling paint.
Should I paint the ceiling first?
Yes, absolutely. Start from the top down: Ceiling - Walls - Trim. This way, if ceiling paint drips onto the walls, you'll just paint over it later.