Stucco Calculator (Bags of Base and Finish Coat)
How many 80 lb bags of stucco you need for a wall: base coat (scratch and brown) bags from the manufacturer's coverage at your system thickness, plus finish coat bags.
Formula
Area = (wall − openings) × (1 + waste). Base bags = area ÷ coverage, where coverage per 80 lb bag = 20–24 sq ft × (3/8 in ÷ base thickness). Finish bags = area ÷ (70 sq ft × 1/8 in ÷ finish thickness).
Worked example
Inputs: Wall area = 1000 sq ft; Windows and doors to subtract = 100 sq ft; Stucco system = Three-coat over lath (scratch 3/8 + brown 3/8 in); Finish coat thickness (0 = none) = 0.125 in; Waste = 10 %.
| Stucco area sq ft | 900 |
|---|---|
| Base coats | Three-coat over lath: scratch 3/8 in + brown 3/8 in |
| Base thickness in | 0.75 |
| Base coverage sq ft per bag | 10–12 |
| Base coat bags 80lb conservative | 99 |
| Base coat bags 80lb best case | 83 |
| Finish coat bags 80lb | 15 |
| Base coat cu ft | 61.88 |
Base coat coverage from the QUIKRETE Scratch and Brown data sheet (80 lb bag: 20–24 sq ft at 3/8 in, 15–18 at 1/2 in, 10–12 at 3/4 in), scaled to the coat thickness. Finish coat: about 70 sq ft per 80 lb bag at 1/8 in (QUIKRETE Stucco Selector Guide), scaled. Lath, paper, trim and weep screed are not included.
FAQ
How many bags of stucco do I need per 100 sq ft?
For a three-coat system (3/4 in of base coat), 9 to 10 bags of base coat at 10–12 sq ft per bag, plus 2 bags of finish coat at 1/8 in. Add waste on top.
How much does an 80 lb bag of stucco cover?
QUIKRETE's data sheet for its Scratch and Brown base coat: 20–24 sq ft at 3/8 in, 15–18 at 1/2 in and 10–12 at 3/4 in. The bag yields about 0.75 cu ft.
How thick is three-coat stucco?
Scratch coat 3/8 in, brown coat 3/8 in and a finish coat of 1/8 to 1/4 in, close to 1 in in total. Two-coat stucco over masonry skips the scratch coat.
How many bags for 1,000 sq ft of wall?
With 100 sq ft of openings and 10% waste, about 83 to 99 bags of base coat for three-coat work and 15 bags of finish coat at 1/8 in.
Does this include lath and paper?
No. It counts only stucco bags. Lath, building paper, weep screed and trim accessories are separate.
Sources
- QUIKRETE Scratch and Brown Base Coat Stucco (No. 1139) data sheet: 80 lb bag yields about 0.75 cu ft and covers 20–24 sq ft at 3/8 in, 15–18 at 1/2 in, 10–12 at 3/4 in
- QUIKRETE Stucco Selector Guide: Finish Coat Stucco about 70 sq ft per 80 lb bag at 1/8 in
- QUIKRETE Stucco Products and Wall Systems (dealer training): three-coat system scratch 3/8 in, brown 3/8 in, finish 1/8–1/4 in; two-coat over masonry brown 3/8 in (1/2 in over porous masonry)
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Last reviewed 2026-10-30.