Paint Cost Calculator: How Much Will Your Paint Project Cost?

When you’re planning to paint a room, one of the first questions is always the same:

“How much will this actually cost?”

Paint estimates often fail because people underestimate the number of coats, don’t account for wall texture, or forget primer and supplies. The calculator below solves this – just enter your wall area, paint coverage, number of coats, and price per gallon. It instantly computes how much paint you need and the total cost of your project.

This tool is perfect for homeowners, DIY painters, contractors, and anyone budgeting a renovation.

🧱 How to Measure Wall Area for Painting

To get an accurate paint estimate, you first need the total wall square footage. The basic formula:

Wall Area = Perimeter × Wall Height − Doors − Windows

Example:

• Perimeter: 44 ft
• Wall height: 8 ft
• Door + window area: 51 sq ft

Total paintable wall area = 44 × 8 − 51 = 301 sq ft

Your paint cost calculator uses this number directly.

👉 Try the Wall Area Calculator

🎨 How Much Paint Do You Really Need?

Most paint cans list their coverage as 350–400 sq ft per gallon, but in practice, coverage varies based on:

• Wall texture
• New drywall vs previously painted walls
• Paint sheen (matte vs glossy)
• Quality of paint
• Porous or stained surfaces

A good rule of thumb:

• Smooth walls: 350–400 sq ft per gallon
• Textured walls: 250–300 sq ft per gallon
• Fresh drywall: always plan primer + 2 coats

The calculator defaults to 350 sq ft per gallon, which works for most homes.

🖌️ How Many Coats Should You Apply?

This affects cost significantly.

Recommended coat counts:

• Repainting similar color: 1–2 coats
• Changing color (light → dark or vice versa): 2–3 coats
• New drywall: 1 coat primer + 2 coats paint
• Textured walls: add 1 extra coat

The calculator multiplies your paint usage by the number of coats to give an accurate estimate.

💰 Paint Price Guide

Paint prices vary widely depending on quality:

Budget Paint ($20–$30/gallon)

• Good for garages, rental properties, closets
• Lower coverage, needs more coats

Mid-Range Paint ($35–$60/gallon)

• Ideal for most rooms
• Better coverage, fewer coats
• Good durability

Premium Paint ($60–$90+/gallon)

• Highest coverage
• Excellent for bold colors
• Best washability and lifespan

Your final project cost depends heavily on your paint quality choice, which is why the calculator includes a price per gallon input.

📦 Supplies You’ll Also Need

These are great for optional affiliate links:

• Rollers and roller frames
• Brushes (angled brush for corners)
• Paint trays + liners
• Painter’s tape
• Drop cloths
• Extension pole
• Primer
• Spackle + sanding block

Homeowners often forget these, so adding a checklist increases time on page and monetization.

⚠️ Common Mistakes When Estimating Paint Cost

People often underestimate paint costs because they:

• Forget about primer
• Use only the raw coverage number
• Ignore porous or textured walls
• Don’t include multiple coats
• Forget ceiling or trim costs
• Round down instead of up
• Forget waste (spills, touch-ups, edge work)

This calculator automatically rounds gallons up, because stores don’t sell fractional cans.

🧮 Example Paint Cost Calculation

Let’s run a real example.

Room wall area: 300 sq ft
Coverage: 350 sq ft/gallon
Coats: 2
Paint price: $40/gallon

Gallons Needed = (300 × 2) ÷ 350 = 1.71 → rounds to 2 gallons
Total Cost = 2 × $40 = $80

This is exactly what the calculator outputs.

🏁 Final Thoughts

A paint job is one of the fastest and most affordable ways to transform a room – but only if you budget correctly. This Paint Cost Calculator takes the guesswork out of estimating paint quantity and cost so you don’t overspend or run out of paint mid-project.