Stucco and Plaster Calculator
Project inputs
Use label yield when you have it. Presets only fill planning defaults that you can adjust.
Coats and yield
Results
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Formulas and assumptions
This tool estimates material from wet coating volume. Product labels may quote coverage differently because aggregate size, water, substrate suction, trowel technique, texture, pump loss, and packaging vary.
- Gross wall area:
wall length x wall height x wall count, or the known area you enter. - Net wall area:
gross wall area - openings - Total coat area:
net wall area x coat count - Total thickness:
coat count x average thickness per coat - Wet volume:
net wall area x total thickness - Waste-adjusted volume:
wet volume x (1 + waste% / 100) - Bags:
waste-adjusted volume / wet yield per bag, rounded up when selected.
How to measure a stucco or plaster wall
- Measure each wall face from finished corner to finished corner and from base to top of the coated area.
- Multiply length by height, then add similar walls or enter the total known takeoff area.
- Subtract large openings such as doors, windows, vents, and uncoated panels.
- Choose the coat count and wet thickness that match your specification or manufacturer instructions.
- Use the bag yield on the product label, then add waste for texture, substrate roughness, mixing loss, and cleanup.
About the presets
The presets are starting points for planning, not material specifications. Three-coat stucco uses a total default thickness near 7/8 inch spread across three coats. One-coat stucco or render uses a thinner base default. Skim coat uses a very thin average coat. Always replace these defaults with the project specification and the yield stated on the exact product bag.
Limits and ordering note
This is a material estimator only. It does not evaluate substrate preparation, lath, mesh, beads, bonding agent, waterproofing, drainage plane, control joints, fire rating, curing conditions, or local code. Confirm final quantities with the product manufacturer, supplier, or qualified installer before ordering.
Stucco and plaster FAQs
How many square feet does a bag cover?
Coverage per bag depends on yield and thickness. The calculator reports coverage per bag at your selected thickness. For example, a 0.60 cu ft bag spread 3/8 inch thick covers about 19 sq ft before waste.
Should I enter each coat separately?
Use the average thickness per coat when the coats are similar. If scratch, brown, and finish coats use very different products, run the calculator once for each product layer.
Can this estimate repairs or patches?
Yes. Use known area mode for patch area and enter the repair thickness. Small repairs often need a higher waste percentage because minimum mixing quantities and tool loss are proportionally larger.
Does this include primer, mesh, corner beads, or fasteners?
No. It estimates wet coating material only. Accessories, substrate preparation, bonding agents, reinforcement, sealers, and finish coatings need separate takeoffs.