Metal Roofing Panel and Cost Calculator
Estimate exposed-width metal panels, ordered linear feet, underlayment, fasteners, trim, waste, and editable material cost.
How to use the metal roofing calculator
- Measure the actual project. Break irregular work into separate sections and record finished dimensions consistently.
- Enter the core measurements. The quick view focuses on project geometry; add or subtract sections where the calculator supports multiple areas.
- Review purchasing assumptions. Open Advanced inputs to replace example prices, waste, coverage, density, pack size, minimum order, or delivery assumptions with current project information.
- Calculate and verify. Review the formula, limitations, whole-unit rounding, product instructions, and supplier requirements before purchasing.
Key inputs covered: Panel effective coverage width, Cut and lap allowance, Panel example price, Underlayment roll coverage, Underlayment roll price, Fasteners per roofing square, Fasteners per pack, Fastener pack price, Ridge, rake, eave, and valley trim, Trim example price, and additional project-specific assumptions.
Result coverage: The metal roofing calculator reports 7 separate quantities so the primary estimate and its supporting purchase or planning values can be checked together.
Estimate metal roofing panels and materials
Enter each roof plane and the panel's effective coverage width to calculate whole panels, ordered linear feet, underlayment, fasteners, trim, and cost.
Effective panel coverage
Use the installed coverage after sidelap, not the panel's full manufactured width. Panel counts round up independently for every roof plane.
Panel length and trim
Slope length drives ordered panel length. Confirm maximum lengths, endlaps, valleys, penetrations, ridge, rake, eave, and flashing details with the roofing system manufacturer.
How the estimate works
Each roof-plane eave width rounds up to whole effective panel widths; panel length follows slope length, then waste, underlayment, fasteners, trim, and editable prices are applied.
A 30 ft eave using 3 ft effective panels needs 10 panels per roof plane before allowance.
Assumptions, rounding, and limitations
Dimensions are treated as finished measurements. Only deductions and allowances entered above are included. Decimal measurements display to two places; purchase quantities round up when a whole container or piece is required.
- Effective coverage width is not the full panel width; use the selected profile manufacturer's sidelap dimension.
- This calculator does not design framing, clips, fastening patterns, wind uplift, snow loads, condensation control, flashing, ventilation, or fall protection.
- Confirm field measurements, maximum panel lengths, endlaps, penetrations, valleys, trim details, substrate, coatings, and manufacturer installation requirements.
Sources and review
These references support unit conversions and selected planning assumptions. Product instructions and local requirements control the actual project.
Last reviewed: 2026-10-09
Editorial process
BuildPlanCalc publishes the formula, editable assumptions, limitations, and supporting references so the estimate can be checked rather than treated as a black box. See the calculation and review methodology, or report a correction.
Frequently asked questions
Are the results exact?
No. Results are planning estimates based on the dimensions and assumptions entered. Confirm product coverage, site conditions, and ordering rules with the supplier.
Why does panel width round up by roof plane?
A partial remaining width still generally requires another panel, and panels from separate planes cannot automatically be combined without a verified cut plan.