Calculate preliminary metal roofing sheet quantities from roof geometry, sheet dimensions, laps and waste.
Roof Geometry
Roofing Sheet
Sheet width is reduced by the side lap when estimating the number of sheets across a roof slope. Sheet length is reduced by the end lap when multiple sheets are needed along the slope.
Ridge and Accessories
Ready to calculate. Press Calculate Roofing Sheets.
Roofing Material Estimate
Estimated Roofing Sheets
—
Roof Area
—
actual slope area
Effective Width
—
per sheet
Slope Length
—
one slope
Ridge Caps
—
stock pieces
Fasteners
—
pieces
Roof Geometry Preview
Metal Roofing Sheets
The preview is a simplified roof illustration and is not a construction drawing.
Detailed Material Takeoff
Material
Base Requirement
Waste / Extra
Total
Stock Size
Stock Pieces
Calculation Summary
Roof Geometry
Ridge / roof length—
Horizontal roof width—
Roof pitch—
Sloping roof length—
Roof area—
Sheet Layout
Effective sheet width—
Effective sheet length—
Sheets across slope—
Sheets along slope—
Roof slopes—
Roof Slope Calculation
For a symmetrical gable roof, the horizontal run of one roof slope is half the overall roof width. The slope length is calculated from the run and the roof pitch.
Run = Overall Roof Width ÷ 2
Slope Length = Run ÷ cos(Pitch)
The eave overhang is added to the slope length so the sheet coverage extends beyond the wall line.
Sheet Quantity Calculation
The effective sheet width is the overall sheet width minus the side lap. The number of sheets required across each roof slope is then rounded upward.
Effective Sheet Width = Sheet Width − Side Lap
Sheets Across = Ceiling(Roof Length ÷ Effective Sheet Width)
If one stock sheet does not cover the complete sloping length, additional sheet rows are estimated using the effective sheet length after the end lap.
Effective Sheet Length = Sheet Length − End Lap
Sheets Along Slope = Ceiling(Slope Length ÷ Effective Sheet Length)
Important Limitations
This is a preliminary roofing material estimator.
It does not design the roof structure.
It does not verify purlin spacing or structural capacity.
It does not determine the correct sheet profile.
It does not determine minimum roof pitch for a particular profile.
It does not account for every roof penetration or opening.
Valleys, hips, dormers and irregular roof geometry require separate takeoffs.
Flashings other than the basic ridge allowance are not automatically calculated.
Actual side and end laps depend on the roofing manufacturer's requirements.
Fastener quantities vary with sheet profile, wind zone and fixing pattern.
Use this result for preliminary estimating only. Final sheet lengths, laps, flashings, fasteners and quantities should be checked against the actual roof drawings and the roofing manufacturer's installation requirements.
Frequently Asked Questions
What does the Metal Roofing Sheet Estimator calculate?
It estimates roof slope area, effective sheet coverage, sheet quantity, ridge caps and a basic fastener quantity.
Does it account for roof pitch?
Yes. The calculator uses the entered pitch to determine the sloping roof length from the horizontal roof width.
Does it include sheet overlap?
Yes. Side lap and end lap are deducted from the sheet's nominal coverage dimensions.
Can it estimate both sides of a gable roof?
Yes. A gable roof is calculated as two equal slopes.
Does it calculate ridge caps?
Yes. Ridge cap quantity is estimated from ridge length, stock length and the selected waste allowance.
Can I use the result to place a final roofing order?
No. It is a preliminary estimate. Final quantities should be checked against the roof drawings, actual measurements and manufacturer's specifications.