Screed Calculator: Volume, Weight and Bags
This screed calculator gives you the volume, weight in kilograms, number of bags and edge strip length: enter the room size or area and the screed thickness.
Example: Enter area as: Length and width · Length 5 m · Width 4 m · Screed thickness 50 mm · Dry mortar consumption 2,000 kg/m³ · Allowance for waste and unevenness 5 % · Bag size: 25 kg → Quantity needed: 2,100 kg dry mortar = 84 bags of 25 kg. Source: Wikipedia – Screed (floor screed). Updated: .
How it is calculated
20 m² of screed at 5 cm thick needs 1 m³, so about 2 tonnes of dry mortar at 2,000 kg/m³; with a 5% allowance that is 84 bags of 25 kg. The calculator gives volume, weight and bag count in one step.
How it is calculated
The volume is area times screed thickness. Multiplying by the product’s consumption in kg per m³ gives the weight of dry mortar; divide by the bag size and round up. An allowance of a few percent covers waste and small unevenness in the base. The edge insulation strip equals the perimeter of the room.
What it is useful for
- Estimating material and cost before laying cement or anhydrite screed.
- Planning delivery as bagged material or from a silo.
- Comparing different thicknesses and rooms quickly.
Frequently asked questions
How much screed do I need per m²?
At 5 cm thick it is 0.05 m³ per m², about 100 kg of dry mortar at 2,000 kg/m³. Every centimetre of thickness needs about 20 kg per m².
How many bags of screed do I need?
Total weight divided by the bag size, rounded up. For 20 m² at 5 cm with a 5% allowance that is 84 bags of 25 kg.
How thick does screed have to be?
It depends on the screed type, insulation, heating and loads, and is set in the design (DIN 18560 in Germany). When in doubt, ask the manufacturer or the screeder.
What is the allowance for?
It covers waste, unevenness in the base and leftovers in the mixer. Five to ten percent is usual.
Sources and legal basis
As of: · Editorial policy
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