Calculate how many kilos of spackling or joint compound you need for walls or ceilings, based on area, thickness and number of coats.
The calculator uses a common rule of thumb for compound consumption: roughly 1.3 kg per m² per mm of thickness.
To spackle 20 m² with 2 mm thickness in one coat, you need 20 × 2 × 1.3 × 1 = 52 kg of compound, equivalent to 3 bags of 20 kg.
A typical coat thickness is 1-2 mm per coat. If the surface is very uneven, you may need more coats or local buildup with thicker compound in some spots.
In most cases, two coats give a smoother, finer result than one coat, especially if the surface will be painted. A rougher first coat is often followed by a finer leveling coat.
It varies with product, temperature and humidity, but a rule of thumb is at least 12-24 hours of drying time between coats. Always check the product's instructions for the exact drying time.