Should I calculate metal roofing by full width or coverage width?

Use coverage width. Full width includes the side lap that is hidden under the next panel.

How many screws do I need for metal roofing?

A rough estimate uses screws per square foot or per panel, but the real count should follow the manufacturer's fastening pattern.

Can this estimate corrugated panels?

Yes. Use the actual panel coverage width, length, lap and screw rate for your corrugated or ribbed panel.

Metal Roofing Panel Calculator

Estimate exposed-fastener metal roofing panels, panel coverage, side lap, end lap, screws, ridge trim, eave trim, waste and material cost.

Metal panel profile

Common exposed-fastener panel with 36" coverage · full 38 in / coverage 36 in · 0.98 lb/sq ft

Roof dimensions

Slope length, ft

Ridge length, ft

Roof planes

Roof pitch angle, deg

Panel length, ft

Waste, %

Panel price, $/sq ft

Trim allowances

Panel layout per roof plane: 11 across x 2 rows = 22 panels

Calculate metal roof panels by coverage width

Metal-panel searches expect the calculator to use coverage width, not only full sheet width. Enter the roof slope length, eave length, panel coverage, overlap and waste to estimate whole panels and fasteners.

P an e l s P er R o w = ⌈ \frac{E a v e L e n g t h}{C o v er a g e W i d t h} ⌉

R o w s = ⌈ \frac{S l o p e L e n g t h - E n d L a p}{P an e l L e n g t h - E n d L a p} ⌉

S cr e w s \approx A r e a_{r oo f} \times S cr e w s P er S q u a r e F oo t

Fastener counts are planning estimates; follow the panel manufacturer's pattern.

Panel estimate caveats

Minimum slope, lap detail, fastener pattern and underlayment depend on the panel profile and manufacturer.
Ridge, rake, eave, valley, sidewall and endwall trim are job-specific and should be checked from the roof plan.
Local wind, snow and code requirements can change attachment, gauge and substrate requirements.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: May 29, 2026

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