Paint Calculator - Calculate Paint & Primer

<h2>Paint Calculator - Calculate Paint Needs</h2> <p>Calculate paint requirements instantly with our free calculator. Get accurate estimates for interior and exterior painting projects including gallons needed, primer requirements, and total project cost.</p> <h2>Calculate Your Paint Needs</h2> <p><strong>Project Type:</strong></p> <ul> <li>Interior Walls</li> <li>Exterior Walls</li> <li>Ceiling</li> <li>Trim/Doors</li> <li>All Surfaces</li> </ul> <p>[Select Project Type]</p> <p><strong>Room Dimensions:</strong></p> <ul> <li>Room Length: [Input] feet</li> <li>Room Width: [Input] feet</li> <li>Wall Height: [Input] feet (standard 8&#39;)</li> </ul> <p><strong>Surface Details:</strong></p> <ul> <li>Number of Coats: [Dropdown: 1, 2, 3]</li> <li>Surface Condition: [Dropdown: New/Painted, Raw Drywall, Dark to Light, Patched]</li> <li>Include Ceiling: [Checkbox]</li> <li>Include Trim: [Checkbox]</li> </ul> <p>[Calculate Button]</p> <p><strong>Your Results:</strong></p> <ul> <li><strong>Wall Surface Area:</strong> [Amount] sq ft</li> <li><strong>Paint Needed (including coats):</strong> [Amount] gallons</li> <li><strong>Primer Needed:</strong> [Amount] gallons (if applicable)</li> <li><strong>Total Project Cost:</strong> $[Amount]</li> </ul> <hr> <h2>What is Paint Coverage?</h2> <p><strong>Paint Coverage</strong> refers to the area that one gallon of paint will cover. Most paint manufacturers state coverage on the can, typically 350-400 square feet per gallon.</p> <h3>Standard Coverage Rates</h3> <table> <thead> <tr> <th>Paint Type</th> <th>Coverage per Gallon</th> </tr> </thead> <tbody><tr> <td><strong>Interior Paint</strong></td> <td>350-400 sq ft</td> </tr> <tr> <td><strong>Exterior Paint</strong></td> <td>250-350 sq ft</td> </tr> <tr> <td><strong>Primer</strong></td> <td>200-300 sq ft</td> </tr> <tr> <td><strong>Ceiling Paint</strong></td> <td>350-400 sq ft</td> </tr> <tr> <td><strong>High-Hide/One-Coat</strong></td> <td>400-450 sq ft</td> </tr> <tr> <td><strong>Textured/Rough</strong></td> <td>150-250 sq ft</td> </tr> </tbody></table> <h3>Factors Affecting Coverage</h3> <p><strong>Reduces Coverage:</strong></p> <ul> <li>Rough or textured surfaces</li> <li>Unprimed surfaces</li> <li>Color changes (especially dark to light)</li> <li>Porous surfaces (new drywall, bare wood)</li> <li>Spray application (more overspray)</li> </ul> <p><strong>Improves Coverage:</strong></p> <ul> <li>Smooth, prepainted surfaces</li> <li>Same-color repaints</li> <li>Proper primer application</li> <li>Quality paint and tools</li> </ul> <h2>How to Calculate Paint Needs</h2> <h3>Calculating Wall Area</h3> <p><strong>Formula:</strong></p> <pre><code>(Perimeter × Height) - Openings = Wall Surface Area </code></pre> <p><strong>Example (12&#39; × 14&#39; room, 8&#39; ceilings):</strong></p> <pre><code>Perimeter: (12 + 14) × 2 = 52 linear feet Total Wall Area: 52 × 8 = 416 sq ft

Subtract Openings:

• Window: 3&#39; × 4&#39; = 12 sq ft
• Door: 3&#39; × 6&#39;8&quot; (6.67&#39;) = 20 sq ft

Total Openings: 32 sq ft

Net Wall Area: 416 - 32 = 384 sq ft </code></pre> <h3>Calculating Ceiling Area</h3> <p><strong>Formula:</strong></p> <pre><code>Length × Width = Ceiling Area </code></pre> <p><strong>Example:</strong></p> <pre><code>Ceiling: 12&#39; × 14&#39; = 168 sq ft </code></pre> <h3>Calculating Paint Needed</h3> <p><strong>Formula:</strong></p> <pre><code>(Surface Area ÷ Coverage Rate) × Number of Coats = Gallons Needed </code></pre> <p><strong>Example (384 sq ft walls, 350 coverage, 2 coats):</strong></p> <pre><code>First coat: 384 ÷ 350 = 1.1 gallons Second coat: 384 ÷ 350 = 1.1 gallons Total: 2.2 gallons Round up: 3 gallons </code></pre> <h3>Multiple Rooms</h3> <p><strong>Total all rooms:</strong></p> <pre><code>Room 1 + Room 2 + Room 3... = Total Surface Area Then calculate paint needed </code></pre> <p><strong>Example:</strong></p> <pre><code>Living Room: 384 sq ft Bedroom 1: 320 sq ft Bedroom 2: 320 sq ft Hallway: 180 sq ft Total: 1,204 sq ft

Paint (2 coats): (1,204 ÷ 350) × 2 = 6.9 gallons Buy: 7 gallons </code></pre> <h2>Interior Paint Calculator</h2> <h3>Walls Only</h3> <p><strong>Standard Room Example:</strong></p> <pre><code>Room: 12&#39; × 14&#39; with 8&#39; ceilings Wall area: 384 sq ft (after openings)

Two coats of paint: (384 ÷ 350) × 2 = 2.2 gallons Buy: 3 gallons </code></pre> <h3>Walls and Ceiling</h3> <p><strong>Example:</strong></p> <pre><code>Walls: 384 sq ft Ceiling: 168 sq ft Total: 552 sq ft

Two coats walls: (384 ÷ 350) × 2 = 2.2 gallons

One coat ceiling: 168 ÷ 350 = 0.48 gallons Buy: 1 gallon </code></pre> <h3>Including Trim and Doors</h3> <p><strong>Trim Areas:</strong></p> <ul> <li>Baseboard: Perimeter × Height</li> <li>Door casing: Perimeter of doors × Width</li> <li>Window casing: Perimeter of windows × Width</li> </ul> <p><strong>Example:</strong></p> <pre><code>Baseboard: 52&#39; × 4&quot; (0.33&#39;) = 17 sq ft Door casing: 20&#39; × 3&quot; (0.25&#39;) = 5 sq ft Window casing: 14&#39; × 3&quot; (0.25&#39;) = 3.5 sq ft Total trim: 25.5 sq ft

Paint (2 coats): (25.5 ÷ 350) × 2 = 0.15 gallons Included with wall paint (buy 3 gallons total) </code></pre> <h2>Exterior Paint Calculator</h2> <h3>Calculating Exterior Surface Area</h3> <p><strong>Formula:</strong></p> <pre><code>(Perimeter × Height) - Openings = Exterior Wall Area </code></pre> <p><strong>Example (30&#39; × 40&#39; house, 10&#39; walls):</strong></p> <pre><code>Perimeter: (30 + 40) × 2 = 140 linear feet Wall Area: 140 × 10 = 1,400 sq ft

Subtract Openings:

• Windows: 8 windows × 15 sq ft = 120 sq ft
• Doors: 2 doors × 20 sq ft = 40 sq ft

Total Openings: 160 sq ft

Net Wall Area: 1,400 - 160 = 1,240 sq ft </code></pre> <h3>Exterior Paint Needed</h3> <p><strong>Lower coverage (300 sq ft per gallon):</strong></p> <p><strong>Example:</strong></p> <pre><code>Wall area: 1,240 sq ft Coverage: 300 sq ft/gallon (exterior) Coats: 2

Paint needed: (1,240 ÷ 300) × 2 = 8.3 gallons Buy: 9 gallons </code></pre> <h3>Including Soffits and Trim</h3> <p><strong>Soffits:</strong></p> <pre><code>Perimeter × Overhang depth = Soffit Area </code></pre> <p><strong>Example:</strong></p> <pre><code>Perimeter: 140&#39; × 2&#39; overhang = 280 sq ft Paint (2 coats): (280 ÷ 300) × 2 = 1.9 gallons </code></pre> <p><strong>Trim:</strong></p> <ul> <li>Fascia, corner boards, window trim</li> <li>Add 10-15% to wall area for trim</li> </ul> <h2>Primer Calculator</h2> <h3>When to Use Primer</h3> <p><strong>Use Primer:</strong></p> <ul> <li>New drywall or bare wood</li> <li>Patched areas (large patches)</li> <li>Color changes (especially dark to light)</li> <li>Glossy surfaces being repainted</li> <li>Stained or water-damaged areas</li> <li>Raw plaster or masonry</li> </ul> <p><strong>May Not Need Primer:</strong></p> <ul> <li>Same-color repaints</li> <li>Paint already in good condition</li> <li>Using paint-and-primer-in-one products</li> </ul> <h3>Calculating Primer Needed</h3> <p><strong>Formula:</strong></p> <pre><code>Surface Area ÷ Primer Coverage Rate = Gallons of Primer </code></pre> <p><strong>Primer Coverage:</strong></p> <ul> <li>New drywall: 200-250 sq ft/gallon</li> <li>Bare wood: 250-300 sq ft/gallon</li> <li>Previously painted: 300-350 sq ft/gallon</li> </ul> <p><strong>Example (New Drywall):</strong></p> <pre><code>Wall area: 384 sq ft Coverage: 250 sq ft/gallon Primer needed: 384 ÷ 250 = 1.5 gallons Buy: 2 gallons </code></pre> <h3>Spot Priming</h3> <p><strong>For Patches:</strong></p> <ul> <li>Estimate patch area</li> <li>Usually 1 quart is sufficient for most rooms</li> </ul> <p><strong>Rule:</strong></p> <pre><code>If patch area is less than 20% of total, spot prime only </code></pre> <h2>Paint Finish Types</h2> <h3>Sheen Levels</h3> <table> <thead> <tr> <th>Finish</th> <th>Characteristics</th> <th>Best For</th> </tr> </thead> <tbody><tr> <td><strong>Flat/Matte</strong></td> <td>No shine, hides imperfections</td> <td>Ceilings, low-traffic areas</td> </tr> <tr> <td><strong>Eggshell</strong></td> <td>Low sheen, washable</td> <td>Living rooms, bedrooms, halls</td> </tr> <tr> <td><strong>Satin</strong></td> <td>Soft sheen, very washable</td> <td>Kitchens, baths, trim</td> </tr> <tr> <td><strong>Semi-Gloss</strong></td> <td>Shiny, durable</td> <td>Trim, doors, cabinets</td> </tr> <tr> <td><strong>High-Gloss</strong></td> <td>Very shiny, most durable</td> <td>Furniture, doors, accents</td> </tr> </tbody></table> <h3>Selecting the Right Finish</h3> <p><strong>Walls:</strong></p> <ul> <li>High traffic: Satin or eggshell</li> <li>Low traffic: Flat or eggshell</li> <li>Kids&#39; rooms: Eggshell or satin</li> </ul> <p><strong>Trim:</strong></p> <ul> <li>Semi-gloss for easy cleaning</li> <li>High-gloss for dramatic look</li> </ul> <p><strong>Ceilings:</strong></p> <ul> <li>Flat exclusively</li> <li>Ceiling paint specifically formulated</li> </ul> <h2>Number of Coats</h2> <h3>Standard Guidelines</h3> <p><strong>Two Coats:</strong></p> <ul> <li>Most interior/exterior projects</li> <li>Color changes</li> <li>New construction</li> <li>Quality results</li> </ul> <p><strong>One Coat:</strong></p> <ul> <li>Same-color repaints</li> <li>Using high-hide &quot;one-coat&quot; paint</li> <li>Touch-ups and small areas</li> </ul> <p><strong>Three Coats:</strong></p> <ul> <li>Drastic color changes</li> <li>Painting over dark colors</li> <li>Uneven substrate</li> <li>Extra durability needed</li> </ul> <h3>Coat Coverage</h3> <p><strong>Realistic Coverage:</strong></p> <table> <thead> <tr> <th>Coat</th> <th>Coverage %</th> </tr> </thead> <tbody><tr> <td><strong>First Coat</strong></td> <td>70-80% of rated coverage</td> </tr> <tr> <td><strong>Second Coat</strong></td> <td>90-100% of rated coverage</td> </tr> <tr> <td><strong>Third Coat</strong></td> <td>100%+ (builds thickness)</td> </tr> </tbody></table> <p><strong>Example:</strong></p> <pre><code>Wall area: 350 sq ft First coat: 350 ÷ 280 (80%) = 1.25 gallons Second coat: 350 ÷ 315 (90%) = 1.1 gallons Total: 2.35 gallons (buy 3) </code></pre> <h2>Cost Estimation</h2> <h3>Paint Prices (2024 averages)</h3> <p><strong>Interior Paint:</strong></p> <ul> <li>Economy/Contractor: $15-$25 per gallon</li> <li>Mid-Grade: $30-$45 per gallon</li> <li>Premium: $50-$70+ per gallon</li> </ul> <p><strong>Exterior Paint:</strong></p> <ul> <li>Economy: $25-$35 per gallon</li> <li>Mid-Grade: $40-$60 per gallon</li> <li>Premium: $70-$100+ per gallon</li> </ul> <p><strong>Primer:</strong></p> <ul> <li>Standard: $15-$25 per gallon</li> <li>Multi-purpose: $25-$35 per gallon</li> <li>Specialty (stain-blocking): $35-$50 per gallon</li> </ul> <h3>Complete Project Cost Example</h3> <p><strong>Interior Room (12&#39; × 14&#39;, 8&#39; ceilings):</strong></p> <p><strong>Paint Needed:</strong></p> <ul> <li>Walls: 3 gallons (2 coats)</li> <li>Ceiling: 1 gallon</li> <li><strong>Total Paint: 4 gallons</strong></li> </ul> <p><strong>Material Cost:</strong></p> <ul> <li>Wall paint (mid-grade): 3 × $35 = $105</li> <li>Ceiling paint: 1 × $30 = $30</li> <li>Primer (if needed): 2 × $20 = $40</li> <li><strong>Paint Total: $105 + $30 + $40 = $175</strong></li> </ul> <p><strong>Supplies:</strong></p> <ul> <li>Brushes and rollers: $40</li> <li>Tape and drop cloths: $30</li> <li>Tray and liners: $15</li> <li><strong>Supplies Total: $85</strong></li> </ul> <p><strong>Materials Total: $175 + $85 = $260</strong></p> <p><strong>Labor (DIY): $0</strong> <strong>Labor (Hired):</strong> $200-$400</p> <p><strong>Project Total:</strong></p> <ul> <li>DIY: $260</li> <li>Hired: $460-$660</li> </ul> <h3>Exterior House Example</h3> <p><strong>1,240 sq ft exterior walls:</strong></p> <p><strong>Paint:</strong></p> <ul> <li>Body: 9 gallons × $50 = $450</li> <li>Trim: 2 gallons × $55 = $110</li> <li><strong>Paint Total: $560</strong></li> </ul> <p><strong>Supplies:</strong></p> <ul> <li>Brushes, rollers, spray equipment: $150</li> <li>Tape, drop cloths, caulk: $80</li> <li><strong>Supplies Total: $230</strong></li> </ul> <p><strong>Materials Total: $560 + $230 = $790</strong></p> <p><strong>Labor (Hired):</strong> $2,000-$4,000</p> <p><strong>Project Total:</strong></p> <ul> <li>DIY: $790</li> <li>Hired: $2,790-$4,790</li> </ul> <h2>Paint Quality</h2> <h3>Quality Levels</h3> <p><strong>Economy/Contractor Grade:</strong></p> <ul> <li>Lower pigment concentration</li> <li>Less durable</li> <li>May require more coats</li> <li>Best for: Rental properties, temporary situations</li> </ul> <p><strong>Mid-Grade:</strong></p> <ul> <li>Good pigment and durability</li> <li>Most homeowners&#39; choice</li> <li>Good coverage</li> <li>Best for: Most residential projects</li> </ul> <p><strong>Premium:</strong></p> <ul> <li>Highest pigment concentration</li> <li>Best coverage and durability</li> <li>Washable, stain-resistant</li> <li>Best for: High-traffic areas, luxury homes</li> </ul> <h3>Paint Calculator Adjustments</h3> <p><strong>Economy Paint:</strong></p> <ul> <li>Subtract 10% from coverage rate</li> <li>Add extra coat for difficult colors</li> </ul> <p><strong>Premium Paint:</strong></p> <ul> <li>Use full coverage rate</li> <li>May achieve one-coat coverage on same colors</li> </ul> <h2>Common Mistakes</h2> <h3>Mistake 1: Not Accounting for Multiple Coats</h3> <p><strong>Problem:</strong> Calculating based on single coat coverage</p> <p><strong>Solution:</strong> Always calculate for 2 coats minimum. Subtract 10-20% from coverage for first coat</p> <h3>Mistake 2: Ignoring Surface Texture</h3> <p><strong>Problem:</strong> Using standard coverage for textured walls</p> <p><strong>Solution:</strong> Textured surfaces reduce coverage 20-40%. Use 200-250 sq ft per gallon for heavy texture</p> <h3>Mistake 3: Forgetting Primer</h3> <p><strong>Problem:</strong> Not accounting for primer in calculations</p> <p><strong>Solution:</strong> Add primer cost and calculate separately (lower coverage than paint)</p> <h3>Mistake 4: Underestimating Color Change</h3> <p><strong>Problem:</strong> Using standard coverage for dramatic color changes</p> <p><strong>Solution:</strong> Dark to light may need 3 coats or tinted primer. Adjust calculations accordingly</p> <h3>Mistake 5: Not Buying Extra</h3> <p><strong>Problem:</strong> Buying exact calculated amount</p> <p><strong>Solution:</strong> Always buy 10% extra for touch-ups. Keep leftover paint for future repairs</p> <h3>How do I calculate how much paint I need?</h3> <p>Measure the room&#39;s perimeter and height to get wall area. Subtract windows and doors. Divide by paint coverage rate (350 sq ft/gallon typical). Multiply by number of coats. Always round up.</p> <h3>How many gallons of paint do I need for a 12 × 12 room?</h3> <p>12&#39; × 12&#39; room with 8&#39; ceilings: Walls = (12+12) × 2 × 8 = 384 sq ft. Subtract ~30 sq ft for openings = 354 sq ft. Two coats: (354 ÷ 350) × 2 = 2 gallons. Buy 2-3 gallons.</p> <h3>How much does 1 gallon of paint cover?</h3> <p>Standard coverage: 350-400 square feet per gallon. Primer covers 200-300 sq ft. Rough or textured surfaces: 150-250 sq ft. Coverage varies by paint quality and surface condition.</p> <h3>Should I use primer or paint with primer?</h3> <p>Use separate primer for: new drywall, bare wood, major color changes, stained surfaces. Paint-and-primer-in-one works for: same-color repaints, minor color changes, already-painted surfaces in good condition.</p> <h3>How many coats of paint do I need?</h3> <p>Two coats is standard for most projects. One coat for same-color repaints. Three coats for: dramatic color changes (especially dark to light), painting over dark colors, uneven surfaces.</p> <h3>How much extra paint should I buy?</h3> <p>Buy 10% extra for touch-ups and mistakes. Always keep leftover paint for future touch-ups. Unopened paint lasts for years; opened paint lasts 2-5 years if sealed properly.</p> <h3>Do I need to paint ceiling before walls?</h3> <p>Paint ceiling first for best results. Prevents drips on walls. Easier to cut in walls to ceiling than vice versa. Use different paint (ceiling flat vs wall eggshell).</p> <h3>How much does it cost to paint a room interior?</h3> <p>DIY: Paint ($80-$150) + supplies ($80-$100) = $160-$250 per average room. Hired: $2-$4 per sq ft = $300-$600 per average room, including materials.</p> <hr> <h2>Practice Examples</h2> <h3>Example 1: Bedroom Paint Calculation</h3> <p><strong>Room:</strong></p> <ul> <li>10&#39; × 12&#39; with 8&#39; ceilings</li> <li>2 windows (3&#39; × 4&#39;)</li> <li>1 door (3&#39; × 6&#39;8&quot;)</li> </ul> <p><strong>Calculation:</strong></p> <pre><code>Perimeter: (10 + 12) × 2 = 44&#39; Wall area: 44 × 8 = 352 sq ft Openings: (3 × 4 × 2) + (3 × 6.67) = 24 + 20 = 44 sq ft Net walls: 352 - 44 = 308 sq ft

Paint (2 coats): (308 ÷ 350) × 2 = 1.76 gallons Buy: 2 gallons </code></pre> <h3>Example 2: Exterior House</h3> <p><strong>House:</strong></p> <ul> <li>28&#39; × 40&#39; footprint</li> <li>10&#39; wall height</li> <li>10 windows (15 sq ft each)</li> <li>2 doors (20 sq ft each)</li> </ul> <p><strong>Calculation:</strong></p> <pre><code>Perimeter: (28 + 40) × 2 = 136&#39; Wall area: 136 × 10 = 1,360 sq ft Openings: (10 × 15) + (2 × 20) = 190 sq ft Net walls: 1,360 - 190 = 1,170 sq ft

Paint (2 coats, 300 coverage): (1,170 ÷ 300) × 2 = 7.8 gallons Buy: 8 gallons </code></pre> <hr> <h2>Related Calculators</h2> <ul> <li><a href="./wallpaper-calculator.md">Wallpaper Calculator</a></li> <li><a href="./room-size-calculator.md">Room Size Calculator</a></li> <li><a href="./flooring-calculator.md">Flooring Calculator</a></li> <li><a href="./drywall-calculator.md">Drywall Calculator</a></li> <li><a href="./tile-calculator.md">Tile Calculator</a></li> </ul> <hr> <p><strong>Need Help?</strong> Our paint calculator is perfect for homeowners, contractors, and DIYers. Calculate your paint needs now!</p>