Home Paint Calculator
Home painting costs range from a few hundred dollars for a DIY single-room refresh up to $25,000 or more for a pro-painted whole-house job with premium paint. This home paint calculator figures out wall area (interior) or siding area (exterior) from your home size and stories, tells you how many gallons to buy, and estimates total paint plus pro labor so you can budget with confidence.
How the Home Paint Calculator Works
The calculator starts with your home's living square footage and multiplies by standard factors to estimate paint-able area:
- Interior: home sq ft x (ceiling height / 8) x 3.0 for wall area
- Exterior: footprint x 2.5 x stories for siding area
It then divides by the coverage rate (350 sq ft/gal interior, 275 sq ft/gal exterior) and multiplies by the number of coats.
Home Depot Paint Calculator Equivalent
Home Depot sells Behr Premium Plus at roughly $45 per gallon and Glidden at $25 per gallon. A typical Home Depot paint calculator for a 2,000 sq ft interior (walls only, 2 coats, standard paint) outputs about:
- Wall area: 6,000 sq ft
- Gallons needed: 35
- Paint cost: $1,575
- Add labor for pro: $16,500 (at $2.75/sq ft)
- Total: $1,575 DIY materials, $18,000 pro standard
Home Depot free in-store paint color matching is spot-on, and their 1-gallon, 2-gallon, and 5-gallon buckets all ring at the same per-gallon price. Buying 5-gallon buckets saves 10-15 percent over individual gallons for jobs of 10+ gallons.
Exterior Home Paint Calculator
An exterior home paint calculator uses a different coverage rate (275 sq ft/gal vs 350 for interior) because siding is rougher and more porous than drywall. For a 2,000 sq ft single-story home:
- Footprint: 2,000 sq ft
- Siding area: 2,000 x 2.5 = 5,000 sq ft
- Gallons: (5,000 x 2) / 275 = 37 gallons
- Paint cost (standard): $1,665
- Pro labor: $13,750-20,000 (scaffolding for multi-story adds 10 percent per extra floor)
- Total: $15,000-22,000 pro standard
Two-story homes cost 10-15 percent more than single-story for exterior paint because of scaffolding, ladders, and slower production rate on upper floors.
Cost by Home Size
| Home Size | Interior DIY | Interior Pro | Exterior Pro |
|---|---|---|---|
| 1,200 sq ft | $450-600 | $7,500-11,500 | $6,000-10,000 |
| 1,500 sq ft | $600-800 | $9,500-14,500 | $7,500-12,500 |
| 2,000 sq ft | $800-1,100 | $12,500-19,000 | $10,000-16,500 |
| 2,500 sq ft | $1,000-1,400 | $15,500-23,500 | $12,500-20,500 |
| 3,000 sq ft | $1,200-1,700 | $18,500-28,500 | $15,000-24,500 |
Paint Quality - What Actually Matters
- Economy ($25/gal): Glidden or equivalent builder-grade. Needs 3 coats often. 5-7 year lifespan on walls, 4-6 on siding.
- Standard ($45/gal): Behr Premium Plus, Valspar Signature. 2 coats solid, 7-10 year lifespan interior, 6-8 exterior.
- Premium ($70/gal): Sherwin-Williams Duration, Benjamin Moore Aura. 1-2 coats on most walls, 10-15 year interior, 8-12 exterior.
Prep Time Is Where Pros Earn Their Rate
Materials are usually 10-20 percent of a pro paint job. Labor is 80-90 percent. A good exterior prep crew does:
- Pressure wash ($0.20-0.40/sq ft)
- Scrape loose paint
- Fill cracks and nail holes
- Caulk gaps around windows, doors, and trim
- Spot-prime bare wood
- Mask windows, doors, and landscaping
Skipping prep (what economy painters do) causes the new paint to fail in 2-4 years. Proper prep extends exterior paint life to 8-12 years.
DIY Tips
- Buy one extra gallon for touch-ups (or keep receipts for returns at Home Depot)
- Use a 5-gallon bucket and a 3/8 inch nap roller for walls
- Use a 2.5 inch angled sash brush for cutting in
- Plan 150-300 sq ft per hour painting rate including prep
- Temperature must stay 50-90 degrees F for latex paint to cure properly