Bags of stucco for a wall — base and finish coats, plus the lath, for three-coat or two-coat systems.
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Total area of openings. A typical window is 15 ft², a door 21 ft².
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Stucco needed
29 × 80 lb bags
base = ft² ÷ 25 × (0.750 ÷ 0.375); finish = ft² ÷ 70
Calculated with BuildCalculators.com
Calculated with BuildCalculators.com · buildcalculators.com/stucco-calculator
Estimates are for planning only — confirm quantities with your supplier or contractor before ordering.
Stucco is ordered by the bag, and the bag count depends on two things: the wall area you are covering and how thick the system is. Base coat and finish coat are different products with very different coverage — a bag of base covers about 25 square feet at 3/8 inch, a bag of finish about 70 square feet at 1/8 inch — so they are counted separately here rather than lumped into one number.
The system choice sets the base thickness. Three coat over metal lath, the standard for wood-framed walls, applies 3/8 inch of scratch and 3/8 inch of brown before the finish. Two coat goes directly onto concrete block or poured concrete with a single 3/8 inch base and no lath at all.
A = (run × height) − openingsA ÷ 25 × (base thickness ÷ 0.375)A ÷ 70A ÷ 16 ft² usable per sheetThe choice is made by what is behind the stucco, not by preference. Wood framing gets a weather-resistive barrier, then metal lath, then three coats totalling about 7/8 inch — the lath is what the stucco actually grips. Masonry gets two coats straight onto the block, because the block face itself provides the key. Applying a two-coat system to framing has nothing to hold it; the stucco cracks off in sheets. Building the wall as well as rendering it? The concrete-block-calculator covers the blocks, the mortar and the core fill.
Base coat is structural render laid at 3/8 inch a pass; finish coat is a thin decorative skin at about 1/8 inch. Same 80 lb bag, roughly three times the coverage, because it goes on a third as thick. This is why a wall needing 24 bags of base needs only 5 of finish — and why ordering "stucco" without splitting the two leaves you short on one and long on the other.
A standard sheet of metal lath is 27 inches by 8 feet — 18 square feet of material, but sheets overlap at the edges and ends, so the usable coverage is about 16. The calculator uses the usable figure. Lath goes on horizontally, cups up, with the long dimension across the studs, fastened every 6 inches into framing.
Stucco gains strength by hydration, not by drying out, so the enemy is moisture leaving too fast. Mist the scratch and brown coats, keep them damp for the first day or two, and wait — usually 24 to 48 hours between the first two coats, and up to 7 days before the finish on traditional systems. Stucco rushed in hot, windy weather cracks, and no amount of finish coat hides it.
A wood-framed wall with a door and two windows deducted.
29 bags total, plus 19 sheets of lath
Base and finish are separate products at the yard — order 24 of one and 5 of the other, not 29 of something.
Concrete block wall, single base coat, no lath.
17 bags total
Roughly 40% less material than the three-coat system, because the base is half the thickness and the lath disappears. On a painted or sealed block wall, a bonding agent goes on first.
A garden or garage wall, three coat.
16 bags and 10 sheets
Mixing by hand is realistic at this size. Above about 25 bags, hire a mixer — consistency between batches shows in the finish.
Manufacturer published figures, typical across brands.
| Product | Thickness | Coverage |
|---|---|---|
| Base coat | 3/8 in | ≈ 25 ft² |
| Base coat | 3/4 in (two layers) | ≈ 12.5 ft² |
| Finish coat | 1/8 in | ≈ 70 ft² |
| Finish coat | 1/4 in | ≈ 35 ft² |
| System | Layers | Total thickness | Substrate |
|---|---|---|---|
| Three coat | Lath + scratch + brown + finish | ≈ 7/8 in | Wood or steel framing |
| Two coat | Base + finish | ≈ 1/2 in | Concrete block, poured concrete |
| One coat / EIFS | Proprietary systems | Varies | Follow manufacturer spec |
Stucco material is cheap and stucco labour is not. Bags run $10–$18 for base and finish alike in 2026, so a typical 300 ft² wall is $300–$500 in material — against $2,100–$4,500 if a contractor does the whole job at $7–$15 per square foot installed.
Base and finish bags, metal lath at $12–$20 a sheet for three-coat work, weather-resistive barrier, corner bead and casing bead, and fasteners. On a 300 ft² wall the lath and accessories often cost as much as the stucco itself.
Scratch and brown coats are physical but forgiving — they get covered. The finish coat is the one people regret: matching texture across a wall, keeping a wet edge, and stopping cleanly at corners is a skilled trade. Doing your own base coats and hiring the finish is a common and sensible split.
Patching cracks and small areas runs $8–$25 per square foot because the labour is fiddly and matching the existing texture is the hard part. Full recoating over sound existing stucco is often cheaper per foot than patching a wall covered in small failures.
Base and finish coat are different bags with three times different coverage. Turning up with 29 bags of base and none of finish is a wasted trip and a wall left half done.
Without lath there is nothing for stucco to hold on to. It looks fine for a season and then debonds in sheets. Framing gets a barrier and lath, always.
Stucco needs moisture to gain strength. In sun or wind, misting the base coats is what stops the crazing pattern that shows through every finish applied afterwards.
Windows and doors are real deductions, but the returns and reveals around them still get stucco. Deduct the openings, then do not trim the order to the last bag: mixing losses and texture practice consume more than the arithmetic suggests.
One 80 lb bag of base coat covers about 25 ft² at 3/8 inch, and one bag of finish coat covers about 70 ft² at 1/8 inch. A three-coat system needs 3/4 inch of base, so a 300 ft² wall takes roughly 24 base bags and 5 finish bags.
Three coat — scratch, brown and finish over metal lath — is the system for wood-framed walls, totalling about 7/8 inch. Two coat applies a single 3/8 inch base directly to concrete block or poured concrete, where the masonry itself provides the key, so no lath is needed.
About 3.2 lb of base coat per square foot per 3/8 inch layer, and roughly 1.1 lb per square foot of finish coat. Working in bags is more practical: divide your wall area by 25 for each 3/8 inch base layer, and by 70 for the finish.
Typically 24–48 hours between the scratch and brown coats, then 7 days before the finish coat on traditional systems. Mist the base coats to slow drying — stucco that dries too fast cracks, and in hot or windy weather that happens quickly.
Slabs, footings and columns in cubic yards and bags
Installed cost by finish, material shown separately
Grid bar counts, length and weight by size
New or replacement driveway, installed and itemised
Area for rectangles, circles and triangles
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It is a planning estimate. It does not replace an engineer, a site visit or a written quote — confirm quantities with your supplier before ordering.