Short answer
A small 800 sqft bungalow with a 115-foot perimeter and 10-foot walls needs approximately 6 gallons of body paint for 2 coats (the precise figure is 5.82 gallons, so buy 7 gallons to have a safety buffer). That covers 1,018 square feet of paintable wall area. You'll also need 4 quarts of trim paint and about 3 gallons of primer if the surface requires it.
How this calculator works
The calculator takes six inputs and runs them through a straightforward area-minus-openings formula. Here's what each input does and why it matters.
House perimeter (ft): This is the total distance around the outside of your house measured at the foundation. For this bungalow, that's 115 feet. Multiply perimeter by wall height to get gross wall area before any deductions.
Wall height (ft): The average height from the base of the siding to the roofline. On a single-story bungalow, 10 feet is typical — roughly 8 feet of living space plus a foot of foundation exposure and a foot of soffit overhang zone. If your walls vary, use an average.
Doors and windows: Every opening is unpainted wall space. The calculator deducts 21 sq ft per exterior door (a standard 36×80 door with frame) and 15 sq ft per window (roughly a 3×5 opening). With 2 doors and 6 windows, this bungalow loses 42 + 90 = 132 square feet, bringing the gross area of 1,150 sq ft down to 1,018 sq ft of actual paintable surface.
Number of coats: Two coats is the industry standard for any exterior repaint. The formula multiplies paintable area by the number of coats, so a second coat effectively doubles your paint requirement. This is not optional padding — a single-coat exterior paint job fails faster and often voids manufacturer warranties.
Siding factor: Flat or smooth surfaces like fiber cement use 1.0. Vinyl lap siding uses 1.1 because the overlapping channels add hidden surface area. Rough textures like stucco or cedar shake use 1.2 because the paint has to fill grain and texture pores. This bungalow is smooth siding, so the factor is 1.0 and has no multiplying effect.
The core formula:
Paintable area = (perimeter × height) − (doors × 21) − (windows × 15)
Gallons = (paintable area × coats × siding factor) ÷ 350
For this bungalow: (115 × 10) − (2 × 21) − (6 × 15) = 1,018 sq ft. Then 1,018 × 2 × 1.0 ÷ 350 = 5.82 gallons.
The 350 sq ft/gallon coverage rate is deliberately conservative. Paint cans often advertise 400 sq ft/gal, but that assumes a perfectly smooth surface, ideal temperature, and expert application. Real-world exterior conditions — rough edges, porous wood, uneven roller pressure — consistently land closer to 350. Using the higher number leads to short trips back to the paint store.
Secondary outputs:
- Total paintable wall area: 1,018 sq ft — useful if you want to verify or shop coverage-rated products yourself.
- Trim paint: 4 quarts, estimated at 1 quart per 30 linear feet of perimeter. This covers fascia, window casings, corner boards, and door surrounds at typical trim widths. Trim paint is usually a semi-gloss or gloss finish and purchased separately from body paint.
- Primer: 2.9 gallons (round up to 3) for a single primer coat. Primer uses the same 350 sq ft/gal rate and is only calculated for 1 coat since a second primer coat is rarely needed on residential exteriors.
Recommended materials
For a small bungalow repaint, one premium gallon covers the same area as a budget gallon but holds color longer and resists chalking through more seasons. A high-quality exterior paint also tends to level better, which matters on rough-edged bungalow trim. If you're doing the work yourself, an airless sprayer dramatically cuts labor time, but hand tools give better control on detailed trim work. An extension ladder rated for your wall height is non-negotiable for anything above the first 8 feet.
- Behr Marquee exterior paint (1 gallon) — self-priming formula with strong hide; works well on smooth and vinyl siding
- Graco Magnum X5 airless paint sprayer — handles undiluted exterior latex, good for full-house body coats
- Werner D1224-2 24-foot aluminum extension ladder — reaches a 10-foot eave comfortably at the safe working angle
FAQ
How many gallons of paint does a small bungalow exterior need? A typical 800 sqft bungalow with a 115 ft perimeter, 10 ft walls, 2 doors, and 6 windows needs about 6 gallons of body paint for 2 coats. That covers roughly 1,018 square feet of paintable wall area after subtracting doors and windows.
Does the calculator include trim paint? Yes. The secondary output estimates trim paint separately at approximately 1 quart per 30 linear feet of perimeter. For a 115 ft perimeter, that comes to 4 quarts of trim paint.
Do I need primer on top of the 6 gallons? Primer is calculated separately. One coat of primer on this bungalow requires about 3 gallons. You only need primer if you're painting over bare wood, a drastically different color, or a weathered surface.
What coverage rate does the calculator use? The formula uses 350 square feet per gallon, which is a conservative real-world figure for exterior paint applied by brush or roller. Manufacturer labels often claim 400 sq ft/gal but that assumes ideal conditions.
What is the siding factor and when should I change it? The siding factor adjusts for texture. Smooth siding uses 1.0, vinyl lap siding uses 1.1, and rough surfaces like stucco or cedar shake use 1.2 because the paint has more surface area to cover. This bungalow uses 1.0 for smooth siding.
How are doors and windows deducted? Each standard exterior door deducts 21 square feet and each window deducts 15 square feet from the gross wall area. These are average figures; large picture windows or French doors may warrant a manual adjustment.
Should I buy exactly 6 gallons? Round up to 7 gallons. Paint is sold in whole gallons, and having a partial gallon left over is far better than running short mid-coat. Leftover paint also covers touch-ups for years.
Can I use this estimate for spray application? Spray application typically consumes 20–30% more paint due to overspray and the need for multiple thin passes. If you're renting or using an airless sprayer, add at least 1–2 gallons to the estimate.
How long does it take to paint a small bungalow exterior? For a single painter working by hand, expect 2–3 full days for 2 coats on an 800 sqft bungalow. Using an airless sprayer can cut that to 1 day, but prep and masking time stays the same.
Is 2 coats always necessary? Two coats are standard for any exterior repaint and required for color changes. If the existing paint is in excellent condition and you're using the same color, some high-hide paints can cover adequately in one coat, but check the manufacturer's warranty terms first.
Does the calculator account for gable ends or dormers? No. The formula multiplies perimeter by a single wall height, which works for a simple rectangular bungalow. If your home has gable ends, dormers, or varying wall heights, measure those areas separately and add them to the total.