Cement bags and sand needed to plaster walls and ceilings at any thickness and mix.
How this works
Wet plaster volume is area x thickness. Add about 27% for gaps, uneven walls and droppings (dry volume = wet x 1.27). Split by the mix ratio, with cement at 1,440 kg per m³. 12 mm of 1:4 plaster uses about 1 bag of cement per 11 m².
Questions people ask
How do I use the Mortar and Plaster Calculator?
Fill in the fields, starting with “Wall or ceiling area”, “Type of work” and “Custom thickness”, and change any other options that match your home. The answer, a drawing and practical tips update as you type, and the Copy link button saves your numbers in a link you can share.
Is the Mortar and Plaster Calculator free?
Yes. The Mortar and Plaster Calculator is free, with no sign-up, and works on phones, tablets and computers. The results are estimates to help you plan, so check with a qualified professional before structural, electrical, gas or plumbing work.