Plaster calculation is where most wastage happens.
I have seen cement bags thrown away because plaster quantity was guessed.
Plaster Depends On Area and Thickness
Wall area
Plaster thickness
Thickness is usually 0.5 inch.
Example Calculation
Wall area = 400 sqft
Thickness = 0.5 inch = 0.04 feet
Wet volume = 16 cubic feet
Dry volume = 20 cubic feet
Using 1:6 ratio:
Cement = 3 bags
Sand = 17 cubic feet
Common Plaster Mistakes
Ignoring thickness
Using too much water
Changing ratio mid plaster
Practical Tip
Always calculate plaster separately for each room.
Why Plaster Calculators Help
They reduce wastage and control material ordering.
