Overview
Enter the surface area, number of coats, coverage rate, waste allowance, and pack size. The calculator returns material needed without waste, total quantity with waste, and the number of packs to buy.
Use cases
- Bathroom waterproofing estimate before tiling.
- Balcony and terrace liquid membrane planning.
- Foundation damp-proofing material estimate.
- Quick check for how much waterproofing compound to buy.
How it works
- 1
Multiply area by the number of coats.
- 2
Divide by the coverage rate to get base material quantity.
- 3
Add the waste percentage for a safer estimate.
- 4
Divide by pack size and round up to get packs needed.
Examples
Bathroom floor
Input: 10 m², 2 coats, 1 m²/kg coverage, 10% waste, 5 kg pack
Output: 20 kg base, 22 kg total, 5 packs.
A practical estimate for a small bathroom floor.
Terrace waterproofing
Input: 25 m², 2 coats, 0.8 m²/l coverage, 15% waste, 10 l pack
Output: 62.5 l base, 71.9 l total, 8 packs.
Useful when planning outdoor waterproofing materials.
FAQ
What can I calculate with this tool?
You can estimate the amount of waterproofing material needed for bathrooms, balconies, terraces, and foundations.
Does the calculator include waste?
Yes. Enter a waste percentage to get a more realistic total quantity.
Should I round up the number of packs?
Yes. Always round up to ensure you have enough material for the whole job.
Can I use it for liquid membrane?
Yes. It works well for liquid membrane and similar waterproofing products.