Render Calculator
Estimate render area, volume and bags from the wall size, openings, application thickness and product bag weight.
Render quantity calculation
BuildCalcs subtracts the entered openings from the wall area, multiplies the remaining area by the render thickness and converts that wet volume into an approximate material weight.
One coat or multiple coats?
Enter the combined finished thickness you expect to apply. Base coats and finish coats can use different products and yields, so calculate them separately if necessary.
Frequently asked questions
Why might the bag count differ from the bag label?
Real product yield depends on formulation, aggregate size, water addition, substrate texture and wastage. Use the label's stated coverage when buying a specific product.
Can I use this for internal plaster?
The geometry is similar, but material density and product coverage differ. Use the plaster product's own coverage figures rather than assuming render values.