MetraNestManufacturer’s consumption mode
Enter the kilograms per square metre specified for the intended product, tile size and joints. The 0.3 kg/m² value shown in the example is not a general rule. The calculation multiplies this consumption by the area, then adds your reserve and rounds up to the next whole bag.
What geometric mode means
The model compares the area of a tile with that of a module consisting of the tile and its joint. The remaining area fraction, multiplied by the depth, gives a theoretical volume. It assumes regularly repeating rectangles; project edges, bevels and irregularities are not modelled in detail.
Convert volume without confusing materials
To convert this volume into powder to buy, enter the kilograms of powder required per litre of mixed grout, using the product’s yield. The powder’s density in its bag does not provide this conversion. Without an appropriate value, return to the manufacturer’s consumption mode. Perimeter and movement joints remain outside this model.
Manufacturer’s rate mode: kg = area × consumption × (1 + allowance ÷ 100). Geometric mode, dimensions in mm: joint fraction = 1 − L × l ÷ ((L + j) × (l + j)); litres = area in m² × fraction × depth in mm.
Use a consumption rate that matches your project
For 12 m² with an entered consumption of 0.3 kg/m², the requirement is 3.6 kg. A chosen allowance of 10% brings it to 3.96 kg: one 5 kg bag covers this arithmetic estimate.
Details to check
- Check tile size, width and depth in the product table.
- Do not confuse grout yield with powder density.
- Calculate each product separately.
Frequently asked questions
Why two methods?
The first uses product data directly. The second makes the geometry visible, but requires a specific yield to convert litres into a quantity of powder.
Does the result determine joint width?
No. The dimensions are your inputs; the tool does not validate the covering’s design or waterproofing.
Method and references · Editorial review: 25 October 2026
The geometric formulas are explained here. For a product, its packaging dimensions and coverage rate remain the reference inputs.