Calculate your result
Quick answer
For an illustrative 10 m wide plane, 5 m slope run and confirmed 0.686 m cover, use 15 columns. Full-length 5 m sheets need 15 sheets per plane before spares. Two identical planes need 30. These dimensions are an example, not a universal IBR specification.
How it works
Estimate roofing sheets for rectangular roof planes using the confirmed effective cover and actual slope run. Choose full-length sheets or permitted stock-length courses, then compare purchased quantities and your supplier’s quote.
Formula
Columns = ceil(width ÷ effective cover). Courses = max(1, ceil((slope run − end lap) ÷ (stock length − end lap))). Base sheets = columns × courses × identical planes.
Assumptions and common mistakes
Check units, input values and the method before relying on an estimate. Review the existing tool notes and official sources below.
Roofing sheet formula
Columns = ceil(width ÷ effective cover). Courses = max(1, ceil((slope run − end lap) ÷ (stock length − end lap))). Base sheets = columns × courses × identical planes.
| Quantity | Method |
|---|---|
| Columns per plane | Round width ÷ effective cover up |
| Courses per column | Full length: 1; stock courses: account for actual end joints |
| Purchased sheets | Round base plus spare percentage to whole packs |
| Purchased linear metres | Purchased sheets × ordered sheet length |
| Net rectangular roof area | Width × required slope run × identical planes |
How to estimate roofing sheets
Measure the width across one rectangular roof plane and the actual run along its slope, including the required ordered coverage at eaves and ridge. Enter identical plane count only when all those dimensions match. Calculate different planes separately. Do not enter horizontal plan length as slope length; use the Roof Pitch Calculator when a geometric conversion is needed. Hips, valleys, penetrations and shaped sheets require a separate cutting schedule.
Effective cover and side laps
Use the confirmed installed effective cover for the exact profile and prescribed side lap. It is not necessarily the overall sheet width. Side laps are already reflected in effective cover, so do not subtract another side lap. There is no single width for every IBR, corrugated or metal roofing sheet. Confirm the product drawing before ordering.
Full-length sheets or stock courses
Full-length mode orders one specified length per column and checks that it reaches the required slope run. Stock-course mode assumes equal stock lengths and equal specified end laps: covered run = courses × stock length − (courses − 1) × lap. It counts only actual joints. Use that mode only where the selected system permits end laps and its support and sealing details have been specified. It is not a layout or installation approval.
IBR roofing sheet 6 m price and 12 feet sheets
Enter the supplier’s current quote for the exact thickness, coating, profile and ordered length. A 6 m IBR sheet has no universal South African price. Twelve feet equals 3.6576 m, not 6 m. Compare like specifications and the same VAT basis. The tool calculates entered quotes rather than publishing a live price list.
Roofing sheet price per sheet, metre or square metre
Per-sheet prices multiply purchased sheets. Per-linear-metre prices multiply purchased sheets by their ordered stock length. For a square-metre quote, choose effective-cover width or enter the confirmed overall billing width; these bases can differ. The cost uses the purchased material basis, including spare sheets and pack rounding, not just the net roof area. Add separately quoted accessories, labour and delivery once. Zero price lines remain unpriced; no extra VAT is added.
Polycarbonate, transparent PVC and uPVC sheets
Enter the exact product’s confirmed cover and ordered length. Polycarbonate, PVC and uPVC are not interchangeable specifications. Profiles, expansion clearances, UV-facing orientation, support spacing, fixings and permitted laps depend on the manufacturer and application. Matching appearance does not establish compatible profiles or safe spans. Obtain the current installation details; this estimator does not select them.
Aluminium, Aluzinc and other metal sheets
Aluminium sheet and metallic-coated steel are different materials. Names such as Aluzinc or Galvalume describe particular coated-steel products and do not by themselves specify thickness, coating mass or suitability for an exposure. Compare the complete supplier specification, warranty conditions, compatible fasteners and support system. Stone-coated modular roofing needs its own module layout; do not treat it automatically as continuous sheeting.
Which roofing sheet is best or cheapest?
The appropriate option depends on the roof system, exposure, pitch, support design, light transmission needs, maintenance and supplied specification. Compare complete installed quotes, not only the price of one sheet. The calculator does not rank products, design supports, select minimum pitch or calculate fixing quantities from area alone.
Existing asbestos roofs and specialist work
Do not use an ordinary roofing sheet estimate as a removal plan for suspected asbestos-containing material. Arrange identification and compliant assessment before disturbance, and obtain specialist removal and disposal quotes where applicable. This page provides no asbestos sheet sale price, cutting method or manufacturing instructions. Fibreglass fabrication and cutting translucent sheets also require the exact material’s approved procedures.
Reviewed by the 99tools team. Editorial and corrections policy.
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Roofing sheet guides
Frequently asked questions
How do I calculate roofing sheet quantity?
Round roof width divided by confirmed effective cover up to whole columns, then multiply by required courses and identical planes.
Do I subtract side laps again?
No. Confirmed effective cover already accounts for the prescribed side lap.
How many end laps are there?
There is one fewer end lap than courses along a column. A single full-length sheet has no end lap.
What is the price of a 6 m IBR roofing sheet?
Use a current quote for the exact profile, thickness, coating and delivery location. This tool has no live supplier price feed.
How long is a 12 feet roofing sheet?
Twelve feet equals exactly 3.6576 metres.
Can I estimate polycarbonate or PVC sheets?
Yes, for rectangular quantity planning using that exact product’s effective cover, length and permitted lap details.
Does this include fixings and installation?
Only if you enter their separately quoted totals. The tool does not design fixings, support spacing or minimum pitch.
Can I use it for hips and valleys?
The rectangular estimate is not a cutting schedule. Calculate separate planes and have shaped pieces and offcuts checked before ordering.
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Helpful guides
Roofing Sheet Quantities: Effective Cover and End Laps
Calculate whole roofing-sheet columns and stock courses using effective cover, actual slope run and only the end laps between sheets.
Roofing Sheet Prices and Specifications in South Africa
Compare South African roofing sheet quotes by length, cover, material and billing basis, including 6 m IBR and 12 feet sheets.