Estimate the stucco for a wall. Enter the wall area, the number of coats and how thick each one is to get the volume, the bags of premixed stucco, or sand and cement for a site mix, plus the metal lath for framed walls.
Last updated:
Units
sq ft
Perimeter × wall height (add gables)
m²
Perimeter × wall height
sq ft
m²
Number of coats
in
3/8 in = 0.375 is standard
in
in
1/8 in = 0.125 is typical
in
One-coat systems are usually 3/8–1/2 in
mm
mm
mm
mm
Material
Base coats mixed from
ft³
Most 80 lb stucco bags yield about 0.7–0.9 ft³; see the bag
parts
Base coats are commonly 1 cement : 3–4 sand by volume
%
Droppings and uneven walls; 10–20%
Enter your values to see the result.
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How to use the Stucco Calculator
Enter the wall area and the doors and windows to subtract.
Choose the number of coats and check each coat's thickness.
Tick lath if the stucco goes over wood framing or sheathing.
Pick premixed bags or a site mix and set the waste allowance.
Read the bags, volume, sand, cement and lath, and the per-coat table.
Stucco formulas
Net area = wall area − doors and windows
Volume of each coat (ft³) = net area (sq ft) × coat thickness (in) ÷ 12 × (1 + waste)
Premix bags = total volume ÷ yield per bag, rounded up
Site mix: sand ≈ base-coat volume; cement bags = sand ÷ parts of sand per part cement
Lath sheets = net area × 1.05 ÷ 16 sq ft per 27 × 97 in sheet
Example: 1,000 sq ft of wall with 120 sq ft of openings and three coats (3/8 + 3/8 + 1/8 in). Net area 880 sq ft; volume 880 × 0.875 ÷ 12 = 64.2 ft³, or 73.8 ft³ with 15% waste. At 0.8 ft³ per bag that is 93 bags of 80 lb premix, plus 58 sheets of lath.
Common stucco systems
System
Coats
Total thickness
ft³ per 100 sq ft
Three-coat over lath
Scratch 3/8 + brown 3/8 + finish 1/8 in
7/8 in (22 mm)
7.3
Two-coat over masonry
Base 3/8 + finish 1/8 in
1/2 in (13 mm)
4.2
One-coat system
Base 3/8–1/2 in (finish often separate)
3/8–1/2 in
3.1–4.2
Finish coat only
Re-coat over sound stucco
1/8 in (3 mm)
1.0
Tips
Keep each coat damp while it cures, and let base coats cure for the time your mix or local code requires before the next coat.
Remember accessories priced by the foot: weep screed at the bottom of the wall, casing bead around openings, corner aid and control joints.
Gables: add the triangular area (base × height ÷ 2) to the wall area.
Frequently asked questions
How thick is three-coat stucco?
Traditional three-coat stucco is about 7/8 in thick: a 3/8 in scratch coat, a 3/8 in brown coat and a 1/8 in finish coat. Two-coat stucco over concrete or masonry is usually a 3/8 in base coat plus a 1/8 in finish, about 1/2 in in total.
How many square feet does an 80 lb bag of stucco cover?
An 80 lb bag that yields about 0.8 ft³ covers roughly 25 sq ft at 3/8 in or about 75 sq ft at 1/8 in. Bag yields differ, so check the coverage printed on your product.
How do I calculate cubic feet of stucco?
Cubic feet = wall area (sq ft) × total thickness (in) ÷ 12. For 880 sq ft of net wall at 7/8 in: 880 × 0.875 ÷ 12 = 64.2 ft³, or about 74 ft³ with 15% waste.
How much sand and cement do I need for stucco?
Base coats are commonly mixed at about 1 part portland cement to 3–4 parts plaster sand by volume, often with some hydrated lime. Because the cement fills the gaps in the sand, the mixed volume is close to the sand volume, so plan on about 1 ft³ of sand per ft³ of base coat and one 94 lb bag of cement per 3–4 ft³ of sand.
How many sheets of metal lath do I need?
A standard 27 × 97 in sheet is about 18 sq ft, but laps reduce it to roughly 16 sq ft of coverage. Divide the net wall area by 16 and add a few percent for waste and cuts.
Does stucco need lath?
Stucco over wood framing or sheathing needs a weather-resistive barrier (usually two layers) and metal lath fastened to the framing. Stucco applied directly to clean, rough concrete or masonry usually does not need lath, though a bonding agent may be used.
Why add waste to a stucco estimate?
Mixed stucco drops off the hawk and wall, walls are rarely perfectly flat and coats end up thicker in low spots. A 10–20% allowance is common.
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