Paint Coverage Calculator
Paint Coverage Calculator
Calculate the exact amount of paint needed for your interior or exterior painting project. This professional paint calculator estimates gallons required, coverage area, and costs for walls, ceilings, trim, and more.
How to Calculate Paint Coverage:
- Measure wall areas: length × height for each wall
- Subtract openings: doors, windows, and large fixtures
- Add ceiling area if painting ceilings
- Choose paint type and number of coats needed
Standard Paint Coverage Rates:
- Premium paint: 400-450 sq ft per gallon
- Standard paint: 350-400 sq ft per gallon
- Budget paint: 300-350 sq ft per gallon
- Primer: 200-300 sq ft per gallon (varies by surface)
- Textured surfaces: reduce coverage by 20-30%
Surface Type Coverage Adjustments:
- Smooth drywall: standard coverage rates apply
- Textured walls: reduce coverage by 20-25%
- Rough surfaces: reduce coverage by 25-30%
- Previously painted: standard rates (if same color family)
- Bare wood/metal: requires primer, reduce coverage 15%
Paint Types & Applications:
- Latex paint: easy cleanup, fast drying, interior/exterior
- Oil-based paint: durable finish, longer drying time
- Primer: seals surfaces, improves paint adhesion
- Ceiling paint: flat finish, spatter-resistant formula
- Trim paint: high-gloss or semi-gloss for durability
Professional Painting Tips:
- Buy extra paint: add 10% for touch-ups and color matching
- Quality matters: better paint covers more area per gallon
- Primer when needed: dark-to-light colors, bare surfaces
- Multiple thin coats: better than one thick coat
Cost Estimation Tips:
- Paint prices: $25-80 per gallon depending on quality
- Primer prices: $20-50 per gallon
- Professional labor: $2-6 per sq ft depending on complexity
- Supply costs: brushes, rollers, drop cloths, tape
Common Room Measurements:
- Small bedroom: 10×12 ft = ~320 sq ft wall area
- Living room: 14×16 ft = ~480 sq ft wall area
- Standard door: 21 sq ft
- Standard window: 15 sq ft
- 8-foot ceilings: most common residential height
Frequently Asked Questions
How much paint do I need for a 12x12 room?
A 12×12 room with 8-foot ceilings has about 384 sq ft of wall area. Minus doors/windows (~60 sq ft), you need paint for ~320 sq ft. This requires about 1 gallon of quality paint for one coat.
Does primer coverage differ from paint coverage?
Yes, primer typically covers 200-300 sq ft per gallon vs 350-450 for paint. Primer is thicker and designed to seal and prepare surfaces rather than maximize coverage.
How do I calculate paint for textured walls?
Textured walls absorb more paint. Reduce normal coverage rates by 20-30%. If standard coverage is 400 sq ft/gallon, expect 280-320 sq ft/gallon on textured surfaces.
Should I buy paint and primer separately or combined?
Paint-and-primer-in-one works for minor color changes and previously painted surfaces. For bare surfaces, dark-to-light colors, or stains, use separate primer first.
How much extra paint should I buy?
Buy 10-15% extra paint for touch-ups, color variations, and future repairs. Keep leftover paint labeled with room and date for easy matching.
Can I return unused paint?
Most stores accept returns of unopened, untinted paint. Custom colors are usually non-returnable. Check store policies before purchasing large quantities.