Formula
Weight = area × thickness × use per ft² per inch × (1 + waste). Bags = weight ÷ bag size, rounded up.
Example
300 ft² with a ¾-inch coat at 8.8 lb per ft² per inch and 10% waste needs 2,178 lb: 28 bags of 80 lb.
Tips
- Check the coverage on the bag; it varies by product.
- Uneven walls need a thicker coat, so measure a few spots first.
Frequently asked questions
What thickness should plaster have?
A scratch and brown coat often add up to ¾ inch; a thin finish coat is around ⅛ inch.
Does the calculator work for stucco?
Yes, if you enter the coverage from the stucco bag.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.