Calculate the cement bags and sand volume needed to plaster a wall or ceiling, based on your area, plaster thickness, and mix ratio.
Internal walls are typically plastered 12–15mm thick, while external walls often need 15–20mm, sometimes applied in two coats.
A richer 1:3 cement:sand mix is common for ceilings since it needs to bond well overhead and resist cracking.
No — just set 'Number of Coats' to 2 in this calculator and it will scale the cement and sand quantities automatically.