Corrugated Roofing Calculator
Enter your roof's width and length along with your sheet's effective coverage width and length to find how many sheets you need.
Use the sheet's effective coverage width after accounting for side overlap, not its full physical width.
How corrugated roofing sheet quantity is calculated
This calculator divides your roof's width by the sheet's effective coverage width to find how many sheets span across in one row, then divides the roof's length by the sheet's length to find how many rows are needed, rounding each up since partial sheets still require a full sheet.
Corrugated sheets overlap at their edges (typically one or more corrugation ribs) to create a weatherproof seal, so the effective coverage width is always less than the sheet's full physical width — check your specific product's overlap recommendation.
Frequently asked questions
What's the difference between a sheet's physical width and coverage width?
The physical width is the sheet's actual manufactured width, while coverage width accounts for the overlap with the adjacent sheet, which is typically one or more corrugation ribs narrower than the physical width.
How much overlap should corrugated sheets have?
This varies by product and local wind/rain exposure, but a common recommendation is one full corrugation rib of side overlap and 150-200mm (6-8 inches) of end overlap for roofs with a typical pitch — check your manufacturer's specific installation guide.
Does this account for roof ridge caps or flashing?
No — this calculates the main roofing sheets only. Ridge caps, flashing, and trim pieces are typically calculated separately based on the roof's ridge length and edge perimeter.