Paint Calculator

Calculate how much paint you need for interior walls, exterior, ceilings & trim. Includes cost estimator.

Interior Paint Calculator

Calculate paint needed for interior walls. Supports multiple rooms. Note: assumes rectangular rooms — for L-shaped or irregular rooms, split into rectangles and add results.

WALL AREA WALL AREA − DOORS − WINDOWS = PAINT AREA ÷ 350 SQFT/GAL

Interior Paint Results

TIP: Dark-to-light color changes need primer first. Flat/matte hides imperfections. Eggshell & satin are best for living areas. Semi-gloss for kitchens/bathrooms.

Exterior Paint Calculator

Calculate paint for house siding, exterior walls and trim.

Exterior Paint Results

EXTERIOR TIP: Use 100% acrylic paint for durability. Paint in 50-85°F weather. Avoid direct sun — follow the shade around the house. Power wash before painting.

Ceiling & Trim Calculator

Calculate paint for ceilings, baseboards, crown molding and door/window trim.

Ceiling & Trim Results

CEILING: Use flat/matte ceiling paint (hides imperfections). Paint ceilings before walls. For trim, use semi-gloss or high-gloss for durability and easy cleaning.

Painting Cost Calculator

Estimate total painting project costs including paint, primers and labor.

Paint Cost Estimate

SAVE MONEY: Buy paint during holiday sales (30-40% off). Use painter's tape to avoid mistakes. Quality rollers = better coverage = less paint. One gallon of premium can outperform two of budget paint.

How Much Paint Do I Need?

Our paint calculator determines exactly how many gallons you need. Calculate wall area (perimeter × height), subtract openings (doors ~21 sqft, windows ~15 sqft), then divide by coverage (350 sqft/gallon). For 2 coats, multiply by 2. A standard 12×14 room with 8ft ceilings needs about 1.5-2 gallons for 2 coats.

Interior Painting Cost

Interior painting costs $2-$6 per sqft for professional labor. A single room: $300-$800. Full house interior (2,000 sqft): $3,000-$8,000. DIY saves 60-70% — budget $100-$300 per room for paint and supplies.

Exterior Paint Calculator

For exterior paint: measure house perimeter × wall height. Subtract doors, windows and garage openings. Rough surfaces (stucco, brick) absorb more paint — reduce coverage to 150-250 sqft/gallon. A typical house exterior needs 8-15 gallons for 2 coats.

Frequently Asked Questions

How much paint do I need for a 12×12 room?+
Wall area: 48ft perimeter × 8ft = 384 sqft. Minus 2 doors (42) and 2 windows (30) = 312 sqft. At 350 sqft/gal: ~1 gallon per coat, 2 gallons for 2 coats. Buy 2 gallons.
How many square feet does a gallon cover?+
Standard: 350-400 sqft per coat. Textured walls: 250-300 sqft. Primer: 300-350 sqft. Exterior on brick: 150-200 sqft. Always check the paint can label for specific coverage.
How much does it cost to paint a house interior?+
Professional: $2-$6/sqft labor + paint ($30-$75/gal). Average 1,500 sqft home: $3,000-$7,500. DIY: $500-$1,500 for paint/supplies. Large homes (3,000+ sqft): $6,000-$15,000 professional.
Do I need primer before painting?+
Yes for: new drywall, dark-to-light color changes, stains/odors, bare wood, or switching between oil and latex. Paint+primer combos work for same-color touch-ups and light repaints only.