Verify the inputs
Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.
Construction/ CALCULATOR
Underlay rolls from complete room-length strips
Compare roll orders for two laying directions instead of assuming all purchased area can be used.
FROM ESTIMATE TO ACTION
Use the result, not just the number.
Keep the calculation traceable
Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.
Confirm the decision
Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.
Inputs to verify
- Room length along strips (m)
- One rectangular room; swap length and width to compare directions.
- Room width across strips (m)
- Measure the actual boundary; count irregular zones separately.
- Combined end trim per strip (m)
- Both ends together; follow the actual system detail.
- Usable roll width (m)
- Net covered width, excluding any non-covering foil flap.
- Continuous roll length (m)
- Use the actual length; this model does not join short pieces end-to-end.
- Additional complete spare strips (strips)
- Explicit reserve for damage; not a hidden area percentage.