Understanding your result
The headline is the paint or elastomeric for the coats you chose, with the allowance, and the sub-line is the can list with the primer added. The four figures show the area, the coverage used (the typical figure for the product and texture, or your can’s if you entered one), the quantity per coat and the primer.
The breakdown goes from the wall area and openings to the area to paint, then shows the product on the texture with its typical coverage, the coverage actually used, coats, per coat, allowance, total and cans, and finally the masonry primer as its own line with its own cans. For a job this size the cans are 5-gallon pails, and the leftover is shown.
Stucco is one product on one surface, but a house is rarely only stucco. The exterior house paint calculator handles the whole house with a siding factor, and is the better choice for a stucco house that is already painted and sound; this calculator is for the masonry itself, with product-specific rates and a primer. The block filler calculator comes before this one on bare concrete block, and the masonry sealer calculator is the clear alternative where colour is not wanted.
How we calculate this
The area is a rectangle: the length of wall times its height, with the doors and windows taken out at the standard 20 and 15 sq ft from the standard sizes page, or an area you measured. Gables and odd shapes are easier in the exterior house calculator, which has them as fields.
The coverage table is the substance. Acrylic masonry paints quote 200 to 400 sq ft per gallon depending on texture and porosity on their data sheets; the calculator uses 250, 200 and 150 for smooth, medium and heavy. Elastomeric coatings quote 50 to 100 sq ft per gallon per coat because of the film thickness they are designed for; the calculator uses 100, 80 and 65. The coverage rates table lists the published ranges, and the film thickness guide explains why a coating specified in wet mils covers what it covers. The siding guide puts stucco and masonry next to the other surfaces.
Masonry primer and conditioner is costed at 200 sq ft per gallon, the figure the data sheets give for chalky or porous masonry. The rounding to cans is the same as on every calculator here.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Acrylic, smooth / medium / heavy | 250 / 200 / 150 sq ft per gallon | Masonry paint data sheets (Behr Masonry, Stucco & Brick; Sherwin-Williams Loxon Acrylic; Benjamin Moore Ultra Spec Masonry): 200–400 by texture |
| Elastomeric, smooth / medium / heavy | 100 / 80 / 65 sq ft per gallon | Elastomeric data sheets (Behr Elastomeric Masonry, Stucco & Brick; Sherwin-Williams Loxon XP): 50–100 at the specified wet film |
| Masonry primer | 200 sq ft per gallon | Masonry primer and conditioner data sheets (Loxon Conditioner, Behr Masonry Primer): 150–300 |
| Openings | 150 sq ft default | Four windows and two doors at standard sizes; edit to suit |
| Coats | 2 | Manufacturers’ recommendation for both product types |
| Allowance | 5% | Roller loss; use 25–35% if spraying |
Assumptions last reviewed October 7, 2026.
The calculator does not model the cure of new stucco (about 28 days and a pH under 10, from the data sheets), crack filling before an elastomeric, efflorescence treatment, or block filler on bare block, which is its own product and calculator. It does not decide between the products; the siding guide sets out when each one is right.
Two worked examples
A single-storey stucco house, repainted
120 ft of wall at 9 ft, 150 sq ft of doors and windows, medium dash texture, acrylic masonry paint, two coats, chalky old paint so a primer coat first.
- Area: 120 × 9 − 150 = 930 sq ft
- Coverage: acrylic on medium texture, 200 sq ft per gallon
- Per coat: 930 ÷ 200 = 4.65 gallons
- Needed: 4.65 × 2 × 1.05 = 9.77 gallons, buy 2 × 5-gallon pails
- Primer: 930 ÷ 200 × 1.05 = 4.88 gallons, buy 1 pail
Three pails in all. The primer is a pail on its own because chalky stucco drinks it; on sound, previously painted stucco the box can be unticked and the job is two pails.
An elastomeric coating on a cracked block wall
1,000 sq ft of heavily textured, previously painted block, elastomeric, two coats, no primer.
- Coverage: elastomeric on heavy texture, 65 sq ft per gallon
- Per coat: 1,000 ÷ 65 = 15.385 gallons
- Needed: 15.385 × 2 × 1.05 = 32.31 gallons, buy 6 pails + 2 gallons + 2 quarts
Thirty-two gallons for a thousand square feet is the elastomeric reality, and it is sprayed and back-rolled. The same wall in smooth sand-finish stucco with acrylic paint, 2,840 sq ft of a two-storey house with 400 sq ft of openings, needs 23.86 gallons for two coats: four pails and four gallons.
Where to find your inputs
Wall length and height. The perimeter of the stucco walls and their height to the eave, or each wall measured and added. For a house with gables and several storeys, the exterior house calculator is the easier way in; copy its net wall area into the measured-area mode here.
Texture. Run a hand over it. Sand finish and smooth troweled stucco is smooth; dash, lace and knockdown are medium; heavy dash, Spanish lace with deep relief and split-face block are heavy.
Product. Acrylic masonry paint for sound surfaces; elastomeric for hairline cracks and water. The can says which.
Primer. Tick for bare stucco, chalky paint (rub a hand on it; if it comes away white, it is chalky) and new patches. Untick for sound, previously painted masonry.
Common mistakes
- Using ordinary exterior paint on bare stucco. Masonry paints are alkali-resistant; ordinary paint can saponify on fresh lime and cement.
- Painting new stucco too early. 28 days of cure and a pH test; the data sheet is the authority.
- Spreading elastomeric thin. It bridges cracks only at the specified film; thin, it is just expensive paint.
- Skipping the primer on chalky walls. The paint bonds to the chalk, and the chalk lets go.
- Rolling a heavy texture. Pinholes everywhere; spray and back-roll.
- Painting over efflorescence. The white salts push the paint off. Brush them off and let the wall dry first.
Questions people ask
- How much paint does a stucco house take?
- A single-storey house with 120 ft of 9 ft stucco wall and 150 sq ft of openings has 930 sq ft to paint. On a medium dash texture, acrylic masonry paint covers about 200 sq ft per gallon, so two coats with a 5% allowance is 9.77 gallons, two 5-gallon pails, plus a pail of masonry primer if the stucco is bare or chalky.
- Why does elastomeric cover so little?
- Because it is applied at 15 to 20 wet mils per coat, three to four times a normal paint film, so it can stretch over hairline cracks. The data sheets quote 65 to 100 sq ft per gallon per coat. Spreading it thinner to save money gives you an expensive paint without the crack bridging it is bought for.
- Acrylic masonry paint or elastomeric?
- Acrylic for sound stucco and masonry that needs colour and weather protection. Elastomeric for stucco with hairline cracks, or where water is getting in. Elastomeric costs more per square foot, needs a primer on bare surfaces and is hard to paint over later with anything else, so it is not the default.
- Do I need to prime stucco?
- Bare stucco, chalky old paint and new patches need a masonry primer or conditioner, which binds the chalk and evens the absorption so the first coat does not soak in unevenly. Sound, previously painted masonry can be washed and painted. New stucco also needs to cure, usually 28 days, before any of this.
- How does the texture change the quantity?
- The rougher the texture, the more surface there is and the more paint it holds. The calculator drops the coverage from 250 for smooth to 200 for medium and 150 for heavy on acrylic, and from 100 to 80 to 65 on elastomeric, following the ranges on the data sheets. A split-face block wall counts as heavy.
- Should I spray masonry?
- Heavy textures and block are sprayed and back-rolled, because a brush and roller alone leave pinholes in the texture. Smooth and medium stucco can be rolled with a thick nap. Spraying adds 25 to 35% for overspray on top of the figure here.