Last checked
March 28, 2026
We checked the calculator logic, page links, and support content used on this page.
Small-roof felt tool
Shed Felt Calculator
Estimate shed felt rolls and rough cost for sheds, summerhouses, and small outbuildings.
How to use it
Use it as a planning estimate
Use this calculator to build a rough material estimate, then confirm the final order against product data and site conditions.
Why trust it
See how the site is maintained
Read the calculator methodology and editorial policy for the standards behind these pages.
Assumptions
Roofing estimates rely on covered area, lap or overlap allowances, and the fact that roof shape and pitch often increase the real material take-off above a simple plan area.
Common mistakes
Common issues include ignoring overlap, failing to allow for cuts at edges and ridges, and treating every roof as if it behaves like a simple rectangle.
Best use cases
Best for sheds, garages, simple roofs, and early roofing material checks where the buyer needs a fast but practical order estimate.
How to get a better estimate
Check whether the product is sold by effective coverage after laps or by nominal pack size, because that changes the buying count immediately.
Before you buy
Roofing jobs rarely reward under-ordering. A small overage is usually cheaper than the disruption caused by a short finish course or delayed extra delivery.
UK and US note
Terms vary between roofing systems and markets, but overlaps, pitch, edge waste, and actual covered area remain the critical estimate drivers.
Final buying check
Before placing an order, compare product yield, pack size, delivery cost, and whether buying one extra unit is safer than risking a shortfall.
Explore this tool set
Open the full Roofing Estimating tool set to move from quick estimate to deeper guidance.
How do I use the Shed Felt Calculator?
Enter the covered dimensions, choose a realistic waste setting, and use this calculator to build a planning quantity before checking the product yield or pack coverage.
What most affects the Shed Felt Calculator result?
Common issues include ignoring overlap, failing to allow for cuts at edges and ridges, and treating every roof as if it behaves like a simple rectangle.
Should I round the result up?
Roofing jobs rarely reward under-ordering. A small overage is usually cheaper than the disruption caused by a short finish course or delayed extra delivery.