Waste percentage – material need with waste
Order too little and the job stalls; order too much and money sits in the stockroom. This works out how much you actually need to buy in, with a waste allowance matched to the material.
Work out waste and material need
Enter the net need and choose a material (or your own waste allowance) to get the gross quantity to order. Cutting waste and rejects mean you always need to buy more than the clean area.
Guide values – exact waste depends on the shape of the area, the number of cuts and the material format. Always round up to a whole pack and check the supplier’s instructions.
This tool gives an estimate and is an aid – not a finished calculation. Always check the result against drawings, applicable regulations, supplier data and your professional experience before giving a binding price, ordering material or using the file. ByggExp is not responsible for decisions made solely on the basis of the tool.
Want help taking this further?
Briefly describe what you need and we’ll help you with a quote, material and next steps – free of charge. Only the contact field is required.
Guide values for waste per material
- 5% – concrete/casting, insulation, simple rectangular areas.
- 8–10% – decking, floorboard, floor and wall tiles, plasterboard.
- 10–15% – roofs with dormers and hips, sheet metal with many cuts.
How to keep waste down
Plan the laying direction and joints, order the right lengths and coordinate cuts. Still always round up to a whole pack – one pallet too many is cheaper than a production stop and a re-order that risks differing in colour or batch.
Bädda in kalkylatorn gratis på din sajt
Har du en egen sajt, blogg eller kundportal? Bädda in den här kalkylatorn gratis – kopiera koden nedan och klistra in där du vill ha den. En liten länk tillbaka till ByggExp följer med.
Frequently asked questions about waste
- How much waste should I allow?
- Start from the guide value for the material and adjust for the job. Lots of cuts, diagonal laying, dormers and small rooms full of fitted pieces push the percentage up; large straight areas pull it down. When in doubt, take the higher end of the range.
- How is the gross need calculated?
- Gross need = net need × (1 + waste percentage). 120 m² net with 10% waste becomes 120 × 1.10 = 132 m² to order.
- Why do I need to allow for waste?
- No area gets laid without cutting. Fitted pieces, cuts against walls and corners, mis-cuts and broken boards are used up without covering any area. That share belongs in the order from the start, not discovered mid-job.
- Does the calculator cost anything?
- No, it is free and requires no account.