🎨 House Painting Project Calculator

Estimate paint, materials, and labor costs for your painting project

Measure length × height of all walls
Paint Needed
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Materials Cost
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Labor Cost
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Total Project Cost
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Detailed Breakdown

Coverage Area -
Paint Gallons -
Primer Gallons -
Paint Cost -
Primer Cost -
Supplies (brushes, tape, etc.) -
Labor -

📋 Calculation Assumptions

  • One gallon of paint covers approximately 350 sq ft per coat
  • Primer coverage is approximately 300 sq ft per gallon
  • Supplies include brushes, rollers, tape, drop cloths (~$75-$150)
  • Labor rates vary by region and project complexity
  • Does not include wall repair, trim work, or special finishes

How to Use This Painting Project Calculator

This calculator helps homeowners and contractors estimate the complete cost of interior or exterior painting projects. Input your wall area, number of coats, paint quality, and whether you'll hire professionals or DIY to get an instant cost breakdown.

Step-by-Step Instructions

  1. Choose Project Type: Select Interior or Exterior painting
  2. Measure Your Area: Calculate total wall area (length × height for each wall)
  3. Select Number of Coats: Standard is 2 coats; use 3 for dark-to-light color changes
  4. Choose Paint Quality: Budget, standard, premium, or designer paint
  5. Primer Decision: New drywall or dramatic color changes typically need primer
  6. Labor Choice: DIY or professional installation
  7. Calculate: Get instant estimates for paint quantity and total project cost

Example Project: Living Room Interior

Inputs: 800 sq ft wall area, 2 coats, standard paint ($40/gal), primer needed, professional labor

Results: Approximately 6 gallons paint, 3 gallons primer, $490 materials, $2,400 labor = $2,890 total

Understanding Paint Coverage

Standard paint coverage is approximately 350-400 square feet per gallon for smooth surfaces. Textured walls, porous surfaces, or dramatic color changes may require more paint. Our calculator uses 350 sq ft per gallon as a conservative estimate to ensure you have enough.

When to Use Primer

Primer is recommended for:

DIY vs. Professional Painting

DIY painting saves on labor costs but requires time, equipment, and skill. Professional painters typically charge $2-5 per square foot depending on project complexity, ceiling height, and region. Complex projects with high ceilings, intricate trim, or multiple colors cost more.

What's Included in Supplies Cost

The supplies estimate includes:

Cost-Saving Tips

Common Painting Mistakes

Frequently Asked Questions

How do I measure my wall area accurately?

Measure the length and height of each wall and multiply to get square footage. Add all walls together. For accuracy, subtract major openings like windows (15-20 sq ft each) and doors (20-25 sq ft each). Round up to ensure adequate paint.

How many coats of paint do I really need?

Two coats is standard for most projects. Use one coat only for touch-ups or similar color refreshes. Three coats are necessary when going from very dark to light colors, covering bold colors, or painting over red or orange hues.

Should I buy budget or premium paint?

Premium paint has better coverage, durability, and easier application. It often covers in fewer coats, potentially offsetting the higher price. Budget paint works for low-traffic areas or rental properties. High-traffic areas benefit from premium paint's washability.

Do I need different paint for interior vs. exterior?

Yes. Exterior paint is formulated to withstand weather, UV rays, and temperature changes. Interior paint focuses on washability and low VOC emissions. Never use interior paint outdoors or vice versa.

How much do professional painters charge?

Professional painters typically charge $2-5 per square foot for interior work, or $25-50 per hour plus materials. Exterior painting runs $1.50-4 per square foot. Complex projects, high ceilings, and geographic location affect pricing. Always get 3 quotes for major projects.

Can I paint over wallpaper?

Not recommended. Remove wallpaper first for best results. Painting over wallpaper can lead to bubbling, peeling, and uneven texture. If removal isn't possible, use primer designed for wallpaper and test a small area first.

How long does a gallon of paint last in storage?

Unopened paint lasts 10+ years when stored properly. Opened paint lasts 2-5 years if sealed tightly and stored in a cool, dry place. Latex paint freezes and becomes unusable; oil-based paint is more storage-stable.

What's the difference between flat, satin, and gloss finishes?

Flat/matte hides imperfections but isn't washable—best for ceilings and low-traffic areas. Satin/eggshell offers some sheen and is washable—ideal for living rooms and bedrooms. Semi-gloss and gloss are highly washable—best for kitchens, bathrooms, and trim.