Stucco Calculator
Size your stucco mix, sand and lath from wall area and thickness.
What you'll need to order
- stucco base coat mix
- finish coat
- masonry sand
- metal lath
- weather-resistive barrier
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
volume ft³ = area × (thickness ÷ 12) × 1.10
Traditional three-coat stucco is 7/8 inch total: a 3/8 inch scratch coat, 3/8 inch brown coat and 1/8 inch finish. One-coat systems over foam board are thinner but need a different base.
Switch the site to metric — the control is in the footer — and your inputs, your results and the tables below follow. The formula, the constants, the guidance text and the sources stay in US units on purpose: that is how the standards they come from are written, and restating them would detach each figure from the document you are meant to be able to check it against.
Where these numbers come from
- ASTM C926 (Application of Portland Cement-Based Plaster) 2020 — the ⅞ in three-coat thickness — ⅜ in scratch, ⅜ in brown, ⅛ in finish
Standards are revised on a cycle. The edition above is the one this figure was checked against — confirm it against the edition your jurisdiction has adopted.
Worked example
With wall area 1000 sq ft, total stucco thickness 0.875 in, this calculator returns 133.68 bags.
Waste allowance
The headline figure includes a 10% allowance for waste and over-ordering. The exact requirement is shown alongside it.
Stucco for walls of common area
Click through any row to load those measurements. The address bar keeps them, which makes the result something you can paste into a message.
| Job | Size | Stucco mix bags (80 lb) |
|---|---|---|
| Small shed wall | 200 sq ft × 0.875 in | 26.74 bags |
| Garage front | 500 sq ft × 0.875 in | 66.84 bags |
| One elevation of a house | 1000 sq ft × 0.875 in | 133.7 bags |
| Whole small house | 2000 sq ft × 0.875 in | 267.4 bags |
| One-coat system over foam | 1000 sq ft × 0.375 in | 57.29 bags |
Traditional three-coat is ⅞ in total: ⅜ scratch, ⅜ brown, ⅛ finish.
Frequently asked questions
How thick should stucco be?
Seven-eighths of an inch for traditional three-coat over metal lath on a frame wall, and half an inch over masonry. One-coat systems apply at 3/8 to 1/2 inch but require an approved foam substrate.
How many bags of stucco per square foot?
At 7/8 inch thickness, roughly one 80 lb bag per 7.5 sq ft of wall. A 1,000 sq ft wall takes about 134 bags, which is why bulk delivery makes sense on anything larger.
Does stucco need lath?
Over wood framing, yes — self-furring metal lath over two layers of weather-resistive barrier. Over concrete or block, stucco bonds directly provided the surface is clean and roughened.
How long between stucco coats?
Let the scratch coat cure 48 hours and the brown coat seven days before the finish. Rushing it causes cracking as the underlying coat continues to shrink beneath a hardened surface.