Stucco Calculator
Find how many bags of stucco a wall needs.
Default 25 sq ft
Results update as you type.
How it works
Stucco is a cement-based plaster applied to exterior and interior walls, and this calculator estimates how many bags you need to cover a wall. You enter the wall length and height and the coverage one bag provides, and it returns the number of bags and the wall area. The estimate simply divides the wall's area by the per-bag coverage and rounds up, since you buy whole bags. Coverage varies a lot depending on the product and, crucially, the coat and thickness: a traditional three-coat stucco system has a scratch coat, a brown coat, and a thin finish coat, each with different coverage, so a bag might cover 25 square feet at one thickness but much more or less at another. Always check the coverage printed on your specific product for the coat you are applying, and enter that value. Real stucco jobs also account for the number of coats, waste, and losses to the lath and substrate, so consider adding to the estimate or running it separately for each coat. Use this calculator to budget materials for stucco siding, repairs, and decorative finishes. Enter your wall dimensions and coverage per bag to compute the number of stucco bags.
Bags = wall area / coverage per bag
The calculator multiplies the wall length by its height to get the area, then divides by the coverage a single bag provides and rounds up to whole bags. Coverage per bag depends on the product and the thickness of the coat, so adjust it to match your material's stated coverage for the scratch, brown, or finish coat you are applying.
Source:Plastering estimation
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter wall length and wall height.
- 2
Adjust the options
Adjust coverage per bag if they apply — sensible defaults are already set.
- 3
Read your result
Bags needed updates instantly as you type — no button to press.
Frequently asked questions
How many bags of stucco do I need?
Divide the wall area, length times height, by the coverage one bag provides, then round up to whole bags. If a bag covers 25 square feet and your wall is 160 square feet, you need seven bags. Enter your dimensions and the coverage figure from your product to get the exact count for one coat.
How much does a bag of stucco cover?
Coverage depends heavily on the product and the coat. As a rough guide, an 80-pound bag might cover around 25 square feet for a scratch or brown coat at typical thickness, and much more for a thin finish coat. Always use the coverage stated on your specific product, since it varies with mix and application thickness.
Does this account for multiple coats?
No, this estimate is for a single coat at the coverage you enter. Traditional stucco uses three coats, a scratch, a brown, and a finish, each with different coverage and thickness. For a full system, calculate each coat separately using its own coverage figure and add the results, plus a waste allowance for the whole job.
Should I add waste to the estimate?
Yes. Stucco is lost to mixing, spillage, the texture of the lath, and application, so adding around ten percent extra material is prudent. Uneven substrates and heavy textures consume more. Buying a spare bag or two is cheaper than pausing the job to fetch more and risking a visible seam where a batch runs out.
What is the difference between the coats?
In a three-coat system, the scratch coat is the first, keyed layer applied over lath; the brown coat builds thickness and flatness; and the finish coat provides the final color and texture. Each has a different thickness and coverage, so material needs differ per coat, which is why you should estimate them individually.