Home Improvement & DIY Calculators
Tackle your next project with confidence using our essential home improvement and DIY calculators. Accurately estimate material needs for tasks like painting, flooring, and landscaping to save time, money, and reduce waste.
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Paint Coverage Calculator
Calculate paint needed for your room project.
All Home Improvement & DIY Calculators Calculators (1 calculators)
Paint Coverage Calculator
Calculate paint needed for your room project.
Your Complete Guide to Home Improvement Calculators
Planning a home renovation or DIY project? Our free home improvement calculators help you estimate materials, costs, and quantities with precision. Whether you're painting rooms, renovating spaces, or tackling weekend projects, these tools ensure you buy the right amount of materials—saving you money and extra trips to the hardware store.
Paint Coverage Calculator: Perfect Paint Estimates
Our Paint Coverage Calculator takes the guesswork out of painting projects. Whether you're refreshing a single room or repainting your entire home, this calculator determines exactly how much paint you need based on your wall dimensions, number of coats, and paint type. Stop overbuying paint that sits unused or underbuying and making emergency hardware store runs mid-project.
How the Paint Calculator Works
Calculating paint coverage involves several key factors:
Room Measurements
- Wall Length: Measure each wall in feet or meters
- Wall Height: Typically 8-10 feet for standard rooms
- Total Square Footage: Length × Height for each wall
- Ceiling Area: Room length × width if painting ceiling
Deductions & Openings
- Doors: Standard door ≈ 20 sq ft (7ft × 3ft)
- Windows: Varies, typically 15-30 sq ft each
- Built-ins: Cabinets, fireplaces, shelving
- Trim Work: Baseboards, crown molding (optional)
Paint Coverage Standards
Different paint types cover different amounts of surface area per gallon:
| Paint Type | Coverage per Gallon | Best For |
|---|---|---|
| Primer | 200-300 sq ft | Sealing new drywall, covering dark colors |
| Flat/Matte Paint | 350-400 sq ft | Ceilings, low-traffic areas, hiding imperfections |
| Eggshell/Satin | 350-400 sq ft | Living rooms, bedrooms, moderate traffic |
| Semi-Gloss | 350-400 sq ft | Kitchens, bathrooms, trim, doors |
| High-Gloss | 300-350 sq ft | Cabinets, furniture, high-moisture areas |
Step-by-Step: Using the Paint Calculator
Measure Your Room
Measure the length of each wall and the room height. For a 12ft × 15ft room with 8ft ceilings, you have two 12ft walls, two 15ft walls, and 8ft height.
Calculate Wall Area
Total wall area = (12+12+15+15) × 8 = 54 × 8 = 432 sq ft. Don't forget to include ceiling if painting it: 12 × 15 = 180 sq ft.
Subtract Openings
Deduct doors (20 sq ft each) and windows (15-30 sq ft each). Room with 1 door and 2 windows: 432 - 20 - 30 - 30 = 352 sq ft paintable area.
Apply Coverage Rate
352 sq ft ÷ 350 sq ft per gallon = 1.01 gallons for one coat. For two coats: 1.01 × 2 = 2.02 gallons needed.
Add Safety Margin
Always add 10% extra for touch-ups, waste, and errors: 2.02 × 1.10 = 2.22 gallons. Round up to 2.5 gallons or buy 3 gallons total.
Common Painting Scenarios
Standard Bedroom (12' × 12')
- Wall area: ≈ 384 sq ft
- After deductions: ≈ 320 sq ft
- One coat: 1 gallon
- Two coats: 2 gallons
Buy: 2-3 gallons for walls, 1 gallon for ceiling
Living Room (15' × 20')
- Wall area: ≈ 560 sq ft
- After deductions: ≈ 460 sq ft
- One coat: 1.5 gallons
- Two coats: 3 gallons
Buy: 3-4 gallons for walls, 1 gallon for ceiling
Bathroom (8' × 10')
- Wall area: ≈ 288 sq ft
- After deductions: ≈ 200 sq ft
- One coat: 0.6 gallons
- Two coats: 1.2 gallons
Buy: 1-2 gallons (semi-gloss recommended)
Kitchen (12' × 14')
- Wall area: ≈ 416 sq ft
- After cabinets: ≈ 280 sq ft
- One coat: 0.8 gallons
- Two coats: 1.6 gallons
Buy: 2 gallons (satin or semi-gloss)
Professional Painting Tips
Color Selection
- Test samples on wall first
- View in different lighting
- Dark colors need more coats
- Use primer for drastic changes
Timing & Drying
- Allow 2-4 hours between coats
- Full cure: 30 days
- Avoid high humidity days
- Temperature: 50-85°F ideal
Quality Matters
- Premium paint covers better
- Good brushes/rollers essential
- Clean prep work = better results
- Don't skimp on primer
More Home Improvement Tools Coming Soon
We're constantly expanding our home improvement calculator collection. Future calculators will help you with:
Flooring Calculator
Estimate tile, hardwood, laminate, or carpet quantities for any room
Concrete Calculator
Calculate concrete volume for slabs, driveways, patios, and footings
Wallpaper Calculator
Determine rolls needed based on pattern repeat and wall dimensions
Lumber Calculator
Calculate board feet and material costs for framing and woodworking
Drywall Calculator
Estimate sheets, joint compound, and tape for drywall projects
Mulch & Soil Calculator
Calculate cubic yards needed for landscaping and garden beds
Why Use Our Home Improvement Calculators?
- Save Money: Buy the right amount—no waste from overbuying, no delays from underbuying
- Save Time: Get instant estimates without manual calculations or trips to the store
- Professional Results: Plan like a pro with accurate material quantities
- Free Forever: No subscriptions, no hidden features, completely free to use
- Easy to Use: Simple inputs, instant results, clear explanations
- Mobile Friendly: Calculate on-site with your phone or tablet
- No Registration: Start calculating immediately without creating an account
Important Notes
Our calculators provide estimates based on standard industry practices and average coverage rates. Actual material needs may vary based on:
- Surface texture and condition (rough surfaces require more material)
- Application method and technique (spray vs. roller vs. brush)
- Product brand and quality (premium paints often cover better)
- Color changes and coverage (dark to light needs more coats)
- Climate and environmental conditions
Always add 10-15% extra material for safety margin. For professional projects or if uncertain, consult with contractors or store specialists.
Ready to Start Your Project?
Use our paint calculator above to get accurate material estimates for your next home improvement project.
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