Stucco Calculator
Work out the stucco for a wall from its area and coats: bags of scratch, brown and finish coat, sand, lath and the job cost, with a waste allowance. Pick the system, measure the walls and set each coat's thickness; change the coverage per bag to your product's data sheet.
Your numbers
Quikrete's 80 lb base coat and one-coat bags: 20 to 24 sq ft at 3/8 in. Use your product's data sheet.
Quikrete's 80 lb finish coat: about 70 sq ft at 1/8 in. Heavy textures use more.
Woven wire on a 36 in × 150 ft roll: 450.
Your installed labor rate, for the job total.
Base coat bags
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- Finish coat bags
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- Area
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- Total thickness
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The calculation runs in your browser and ParrotNotes does not store your numbers. They sit in the page address so you can bookmark or share the result.
How stucco is estimated
Stucco is bought by the bag and laid on by the coat, so the estimate goes coat by coat. Measure the wall area: the length of each wall times its height, less the windows and doors. Then for each coat, divide the area by what a bag covers at that thickness and add waste. A bag's coverage is its volume spread out, so twice as thick covers half the area: a base coat bag that covers 22 sq ft at 3/8 in covers 11 sq ft at 3/4 in.
Worked example: 120 ft of wall, 9 ft high, with 120 sq ft of windows and doors, is 960 sq ft. Three-coat stucco with 3/8 in scratch and 3/8 in brown is 960 × 2 ÷ 22 = 87.3 bags of pre-mixed base coat, 96 with 10% waste. The 1/8 in finish coat at 70 sq ft a bag is 13.7 bags, 16 with waste. Lath at 18.19 sq ft a sheet with 10% for laps is 59 sheets.
Three-coat, two-coat or one-coat
Three-coat stucco is the traditional system over framed walls: a scratch coat pushed into metal or wire lath and scored, a brown coat that builds the wall straight, and a thin finish coat that carries the color and texture. The IRC requires three coats over lath and 7/8 in total outside over wire lath. It also sets curing times between coats: at least 48 hours before the brown coat and seven days before the finish coat.
Two-coat work goes straight onto masonry or concrete, which needs no lath: a base coat and a finish, 1/2 in minimum over masonry walls in the IRC table. One-coat stucco is a proprietary, fiber-reinforced base coat applied in a single pass over lath (Quikrete's goes on at least 3/8 in), followed by a finish coat; the product's evaluation report sets the rules, not the generic code table.
Coverage per bag by thickness
At the page's defaults, before waste: 22 sq ft per 80 lb bag of pre-mixed base coat at 3/8 in (Quikrete lists 20 to 24, 15 to 18 at 1/2 in and 10 to 12 at 3/4 in), 87 sq ft per bag of stucco cement mixed 1:3 at 3/8 in (Titan America lists 65 at 1/2 in, 52 at 5/8 in and 37 at 7/8 in), and 70 sq ft per bag of finish coat at 1/8 in.
| Base coat thickness | Pre-mixed bag, sq ft | Cement bag (1:3), sq ft |
|---|---|---|
| 3/8 in | 22 | 87 |
| 1/2 in | 16.5 | 65.3 |
| 5/8 in | 13.2 | 52.2 |
| 3/4 in | 11 | 43.5 |
| 7/8 in | 9.4 | 37.3 |
Finish coat at 1/8 in: 70 sq ft a bag; at 1/4 in about 35.
Bagged base coat or mixing your own
Pre-mixed base coat needs only water, and the bag count is the whole order. Mixing on site means bags of stucco cement (or portland cement and lime) plus sand. Titan America's sheet puts one 80 lb bag of stucco cement at about 1 cu ft, mixed with 2-1/2 to 4 parts sand for the scratch coat and 3 to 4 for the brown, and at 1:3 one bag covers about 87 sq ft at 3/8 in. The calculator uses that 87 sq ft and 3 cu ft of sand a bag; change both if you mix leaner or richer.
Sand is sold by the cubic yard or the ton; the calculator gives cubic feet and cubic yards (27 cu ft to the yard). A ton of sand is a different volume depending on how damp and how graded it is, so ask the yard how they sell it. The finish coat is almost always a bagged color coat, so the calculator counts it in bags either way.
Lath
Over wood or steel framing and sheathing, stucco needs lath: expanded metal lath in 27 × 97 in sheets (2.5 or 3.4 lb per square yard, flat or self-furred) or woven wire on a roll. Count the area, add an allowance for laps and cut-offs, and divide by what one piece covers. The 10% the calculator starts with is a starting figure, not a code number; the lath goes on with laps and fastening set by ASTM C1063 and the local code.
The IRC also wants a weep screed at the bottom of framed walls and two layers of water-resistive barrier over wood sheathing. Those are lineal-foot and roll items the calculator does not count, so add them to the order separately.
How this differs from the brick, drywall and siding calculators
The brick calculator counts units and mortar for a masonry wall, the drywall calculator sheets and compound for interior walls, and the siding calculator squares of lap or panel siding. This page is for a cement plaster skin: it works by thickness and coat, turns bag coverage into bags for each coat, counts lath only where the system needs it, and switches between bagged base coat and cement plus sand. For a stucco wall you plan to paint, the paint calculator gives the gallons.
For stucco contractors and building supply reps: what to write down
On the walk-around, note each wall's length and height, every window, door and opening, what the wall is (framing and sheathing, block or concrete), the system and thicknesses in the spec, the texture and color, access for scaffolding or a pump, and what has to be patched or torn off first. Read the numbers back before you leave, so the bag count, the lath and the quote match the house.
Sources, each read on 2026-11-01. Results are estimates; the product's data sheet, its evaluation report and the local code govern:
- Quikrete, Scratch and Brown Base Coat Stucco (No. 1139) data sheet: 80 lb bag, 20 to 24 sq ft at 3/8 in, 15 to 18 at 1/2 in, 10 to 12 at 3/4 in
- Quikrete, One Coat Fiberglass Reinforced Stucco (No. 1200 / 1216) data sheet: coverage per 80 lb bag, 3/8 in minimum, IAPMO ES ER-455
- Quikrete, Finish Coat Stucco (No. 1201) data sheet: 80 lb bag, about 70 sq ft at 1/8 in
- Titan America, Stucco Cement spec sheet: sand per bag by coat, about 87 sq ft per bag at 3/8 in mixed 1:3
- 2015 International Residential Code chapter 7, as printed in the 2015 Seattle Residential Code: R703.7 (coats, lath, weep screed, curing), Tables R702.1(1) thickness and R702.1(3) proportions
- ICC-ES ESR-3497 (reissued March 2026): expanded diamond mesh metal lath, 27 × 97 in sheets
Related: the brick calculator for brick and mortar, the drywall calculator for the inside walls, and the paint calculator for painting the stucco once it has cured.
More for home services and building products sales: Home improvement sales, Building materials sales, Construction daily report.
The wall is measured on the walk-around
Wall lengths, windows and doors, what the wall is made of, the texture and the color all come up when you walk the house with the owner. Record the visit in ParrotNotes: you get a transcript, a summary and the action items, so the estimate matches what you walked.
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