How to Estimate Paint for a House Exterior

The fastest way to estimate exterior paint: measure your home’s perimeter, multiply by wall height, subtract doors and windows, then divide by 300 to get gallons needed. Add 10-15% for texture and waste. Budget $30-$55 per gallon for standard paint and $1.50-$5 per square foot for labor.

That’s the short version. If you want to avoid running short on paint, getting caught off guard by texture waste, or handing a homeowner a number you can’t back up, keep reading. There’s more to it than simple math.

Quick Answer: How Much Paint Does an Exterior Need?

For a typical single-story 1,500 sq ft home, plan for 10-15 gallons of paint and 3-5 gallons of primer. A two-story home in that same footprint might need 18-25 gallons depending on gable area and trim. Costs land between $500-$1,500 in materials alone. Labor adds another $2,250-$7,500 at $1.50-$5 per square foot.

Those ranges feel wide, and they are. Surface texture, surface condition, the number of coats needed, and local labor rates all push numbers up or down. The method below tightens all of that up.

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How Do You Calculate Square Footage for Exterior Paint?

This is where most homeowners and even some less-experienced painters go wrong. They try to calculate roof area, or they use the floor plan square footage. Neither of those is right.

The correct method is the surface area method. You’re painting walls, not floor.

Here is the step-by-step process:

Step 1: Measure the perimeter

Walk around the house and measure each exterior wall from corner to corner. Write down each length. Add them all together for your total perimeter.

Example: A 40 x 60 foot home has a perimeter of (40 + 60 + 40 + 60) = 200 linear feet.

Step 2: Multiply by wall height

For a single-story home with 9-foot walls, that’s 200 x 9 = 1,800 square feet of wall area.

Step 3: Subtract doors and windows

Each standard exterior door is roughly 20 square feet. Each standard window runs about 15 square feet. Garage doors are bigger, roughly 60-80 square feet each.

If the example home has 2 doors, 8 windows, and a 2-car garage door:

• Doors: 2 x 20 = 40 sf
• Windows: 8 x 15 = 120 sf
• Garage door: 70 sf (estimated)
• Total subtract: 230 sf

Paintable wall area: 1,800 - 230 = 1,570 sq ft

Step 4: Add gables for two-story or A-frame homes

Gable triangles add up fast. Measure the base width of each gable and the height, then use (base x height) / 2. Add each gable’s area to your running total.

Step 5: Add trim separately

Fascia boards, soffits, window and door trim, and corner boards all need to be accounted for separately. For a typical home, trim adds 15-25% on top of field area. Trim often gets a different color or sheen, so keeping it separate matters for your materials list.

Use our Paint Calculator to run these numbers automatically once you have your measurements.

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How Does Surface Texture Affect Paint Estimate?

This is the factor that catches people most often. Smooth siding like vinyl or fiber cement paints predictably. Rough surfaces absorb dramatically more paint.

Here is a quick reference table:

Surface Type	Texture Multiplier	Coverage per Gallon
Smooth vinyl or fiber cement	1.00	350-400 sf
Light wood lap siding	1.10-1.15	300-350 sf
Heavy wood lap, cedar shakes	1.20-1.30	250-300 sf
Light stucco, orange peel	1.15-1.20	300-350 sf
Heavy stucco, sand finish	1.25-1.35	250-300 sf
Rough brick or CMU	1.30-1.40	225-275 sf
Weathered or bare wood	1.35-1.50	200-250 sf

Apply the multiplier to your total paintable area to get your adjusted coverage number. Then divide by the actual coverage rate of the paint you’re using (check the label, most exterior paints list 300-400 sf per gallon).

Pro tip on weathered surfaces: Old, dry, weathered wood drinks paint. The first coat almost disappears. On a house that hasn’t been painted in 10+ years, budget for 2 coats minimum and plan on the first coat absorbing heavily. That’s not waste, that’s the wood drinking in moisture before it holds a finish coat properly.

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What Paint Should You Use for a House Exterior?

Not all exterior paints are equal, and the price difference reflects real performance differences, not just brand markup.

Economy paint ($20-$35/gallon)

One coat covers thin. You’ll likely need more coats, which eats the savings. Okay for rentals and low-priority projects. Not recommended if longevity matters.

Standard paint - Behr, Valspar ($30-$55/gallon)

Solid choice for most residential work. Good coverage, reasonable durability. Most homeowners land here.

Premium paint - Benjamin Moore, Sherwin-Williams ($45-$85/gallon)

Better pigment, better binders, better adhesion. One good coat of premium often outperforms two coats of economy. In a wet climate like the Pacific Northwest, premium exterior paint pays for itself in years of additional life. Paint fails faster in wet climates, full stop. Spending an extra $15-$20 per gallon on the front end is a lot cheaper than repainting in 4 years instead of 8.

Primer ($18-$35/gallon)

Always prime bare wood, patched areas, and any surface where the old paint is gone. Skipping primer on bare wood is one of the most common mistakes that leads to peeling within 2-3 years. Figure 1 gallon of primer for every 350-400 sq ft of bare surface.

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Worked Example 1: Single-Story Ranch, Smooth Siding

Home dimensions: 50 x 35 ft footprint, 8-ft walls Siding: Smooth fiber cement Openings: 2 doors (40 sf), 6 windows (90 sf), 1 single garage door (40 sf)

Calculation:

• Perimeter: (50 + 35 + 50 + 35) = 170 lf
• Wall area: 170 x 8 = 1,360 sf
• Subtract openings: 1,360 - 170 = 1,190 sf
• Texture multiplier: 1.00 (smooth)
• Adjusted area: 1,190 sf
• Paint needed at 375 sf/gal: 1,190 / 375 = 3.2 gallons per coat
• Two coats: 6.4 gallons, round up to 7 gallons
• Add trim at 20%: ~1.5 gallons additional
• Primer (assume 400 sf bare patches): ~1 gallon

Material cost at $45/gal premium paint, $25/gal primer:

• 8.5 gallons paint: $383
• 1 gallon primer: $25
• Total materials: ~$408

Labor at $3/sf (typical):

• 1,190 sf x $3 = $3,570

Full project estimate: ~$3,978

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Worked Example 2: Two-Story Home, Heavy Stucco

Home dimensions: 45 x 30 ft footprint, 18-ft total wall height Siding: Heavy sand-finish stucco Openings: 3 doors (60 sf), 12 windows (180 sf) Gables: Two gables, 20 ft wide x 6 ft tall each

Calculation:

• Perimeter: (45 + 30 + 45 + 30) = 150 lf
• Wall area: 150 x 18 = 2,700 sf
• Gables: 2 x (20 x 6 / 2) = 120 sf
• Total gross: 2,820 sf
• Subtract openings: 2,820 - 240 = 2,580 sf
• Texture multiplier: 1.30 (heavy stucco)
• Adjusted area: 2,580 x 1.30 = 3,354 sf
• Paint at 275 sf/gal (rough stucco): 3,354 / 275 = 12.2 gallons per coat
• Two coats: 24.4 gallons, round to 25 gallons
• Trim at 20%: ~5 gallons additional
• Primer (full prime on fresh stucco patches): 3 gallons

Material cost at $50/gal standard paint, $28/gal primer:

• 30 gallons paint: $1,500
• 3 gallons primer: $84
• Total materials: ~$1,584

Labor at $3.50/sf (stucco is harder):

• 2,580 sf x $3.50 = $9,030

Full project estimate: ~$10,614

For a job this size, use the Painting Estimate Calculator to build a full line-item estimate you can hand directly to a homeowner.

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Common Mistakes That Blow Up Paint Estimates

1. Using floor plan square footage

The floor plan is not the wall area. A 2,000 sq ft house does not have 2,000 sq ft of exterior walls. This mistake can put you off by 30-50% in either direction depending on the home’s footprint and height.

2. Ignoring texture completely

Rough stucco and weathered cedar will consume 30-40% more paint than smooth siding. Ignoring this leaves you short on materials mid-job or explaining to a homeowner why you need more money.

3. Forgetting prep time in the labor estimate

Scraping, pressure washing, caulking, masking, and priming all happen before the first coat of paint goes on. A rough exterior can require 30-40% of the total labor budget just in prep. If you’re only pricing the painting and ignoring the prep, your labor number is wrong before you start.

4. Skipping primer on bare wood or patched stucco

Primer is not optional on raw surfaces. A peeling paint job 2 years later is far more expensive to a contractor’s reputation than a few extra gallons of primer today.

5. Not accounting for second coat needs

One coat rarely holds on an exterior. Budget for two coats by default. If a client wants to save money by doing one coat, explain the risk and get it in writing.

6. Not building in a waste factor

Even on smooth surfaces, waste happens. Brush and roller loading, overspray, touchups, areas that need extra coverage. A 10% waste buffer is standard. On textured or rough surfaces, push that to 15-20%.

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What Does Exterior Painting Labor Actually Cost?

Exterior painting labor runs $1.50-$5 per square foot. That wide range reflects real variables:

Condition	Labor Rate Range
Smooth siding, good condition, single story	$1.50-$2.50/sf
Typical home, minor prep, one-two stories	$2.50-$3.50/sf
Heavy texture, significant prep needed	$3.50-$4.50/sf
Multi-story, complex trim, rough condition	$4-$5/sf

The $3/sf number is a reasonable middle-of-the-road estimate for a typical two-coat exterior paint job with moderate prep. Use it as a starting point, then adjust based on what you actually see when you walk the job.

High-humidity regions and PNW climates add prep time. Peeling paint, moisture damage behind the siding, mildew on the north-facing walls. All of that has to be cleaned and treated before you can apply finish coats. Budget for it.

Regional note: Paint estimates in the Pacific Northwest and similar wet climates should include a premium for prep and for paint quality. The moisture cycling here is brutal on exterior coatings. A $45/gallon premium paint that lasts 8-10 years is the better call over a $28 budget option that starts cracking in 4.

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FAQ: Estimating Exterior Paint

How many gallons of paint do I need for a 2,000 sq ft house exterior?

That depends on the siding type and how you define “2,000 sq ft.” If the total paintable wall area is 2,000 sq ft with smooth siding, plan for about 12-14 gallons for two coats. With rough texture, that number climbs to 16-20 gallons. Use the surface area method above to calculate your actual paintable area, not the floor plan.

How much does it cost to paint the exterior of a 1,500 sq ft house?

A typical exterior paint job on a 1,500 sq ft home runs $2,500-$6,000 all in, including materials and labor. Simple homes with good existing paint in good condition land lower. Homes needing heavy prep, multiple colors, or complex trim work land higher.

Do I need to prime before painting an exterior?

Yes, on any bare wood, repaired stucco, or surface where the old paint is gone or peeling. Skipping primer on bare surfaces is the most common cause of premature peeling. On surfaces with a solid, well-adhered existing paint job, a solid primer coat is still recommended if you are changing colors significantly or going over a dark color with a lighter one.

How do I estimate paint for textured stucco?

Use a texture multiplier of 1.25-1.35 for heavy stucco. That means your actual paint consumption will be 25-35% higher than for smooth siding. Sand-finish stucco also covers fewer square feet per gallon, typically 250-300 sf rather than 350-400 sf. Run both corrections when calculating your gallon count.

How much waste should I factor into a paint estimate?

Add 10% waste on smooth surfaces and 15-20% on rough or textured surfaces. Always round gallon totals up, not down. Running out of paint mid-coat on an exterior is a problem, especially if the batch is mixed and you need to color-match a second batch to finish.

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Try EstimationPro free and skip the manual math. Upload your project notes, measurements, or photos and get a complete exterior paint estimate in minutes, not hours.

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Pro Tips for Cleaner Paint Estimates

• Walk every elevation. Don’t estimate from photos or floor plans. Walk all four sides of the house and note what you see: condition of existing paint, texture variations, hard-to-reach areas, trim complexity.
• Photograph the worst spots. Peeling corners, mildew on north walls, failed caulk lines. These become scope line items and protect you from scope creep disputes later.
• Separate field, trim, and accent colors. Different colors mean different materials lists. A house with three exterior colors needs three separate material calculations.
• Include a fuel and staging line. A two-story job needs scaffolding or a lift. That cost belongs in the estimate, not in your margin.
• Use consistent coverage assumptions. Pick a number (350 sf/gal for smooth, 275 sf/gal for rough) and apply it consistently across every job. Consistency lets you compare actuals to estimates and improve over time.
• Document your logic. Write down how you calculated your estimate. If a homeowner questions a line item, you can walk them through the math. That transparency builds trust and separates you from contractors who just throw a number out.

Measure twice. Estimate right. And if the surface is telling you something is wrong underneath, listen to it before you commit to a price.

For a deeper look at labor pricing by task and production rate, see our guide on painting labor cost per square foot. And for help figuring out exactly how much paint to buy for any job, How Much Paint Do I Need? covers the calculation from wall area to gallons.

Try EstimationPro free and get your exterior paint estimates done right, the first time.