Metal Roofing Calculator to estimate metal roof panels, custom panel length, total linear feet, roof coverage, material cost, and complete project cost for standing-seam or corrugated roofing.
Home & Construction Calculators
Calculate metal roofing panels and costs from the dimensions of one or more identical roof planes.
Use the panel’s effective coverage width after side-lap. Measure slope length along the roof surface and eave width horizontally across each roof plane.
About the Metal Roofing Calculator
This metal roofing calculator estimates panels for standing-seam, exposed-fastener, corrugated, and ribbed metal roofing. It uses the actual panel coverage width to determine the number of panels across each eave, then calculates order length, total linear feet, material cost, and the estimated project total.
Formula and assumptions
Net roof area = slope length × eave width × number of planes. Panels per plane = eave width in inches ÷ effective panel coverage width, rounded up. Total panels = panels per plane × number of planes. Order length per panel = slope length × (1 + length allowance ÷ 100). Total panel length = total panels × order length. Material cost = total panel length × price per linear foot. Project total = material cost + labor, trim, delivery, and extras.
Worked example
For two roof planes with an 18 ft slope length and a 30 ft eave width, using 36 in coverage panels requires 10 panels per plane and 20 panels total. A 5% length allowance produces an 18.90 ft order length and 378 total linear feet. At $4.25 per linear foot, material costs about $1,606.50. Adding $2,500 for labor, trim, delivery, and extras gives an estimated total of $4,106.50.
Measurement checklist
- Measure roof slope length along the surface, not the horizontal run.
- Use effective coverage width rather than full manufactured panel width.
- Measure valleys, hips, dormers, and unequal planes separately.
- Confirm whether panels can be supplied in the required custom length.
Manual calculation steps
- Convert eave width to inches.
- Divide by effective panel width and round up.
- Multiply by the number of identical roof planes.
- Add the selected length allowance to slope length.
- Multiply total panels by order length.
- Apply price per linear foot and add other project costs.
Frequently asked questions
What panel width should I enter?
Enter the effective coverage width after side-lap or seam engagement, not necessarily the panel’s full manufactured width.
Does the calculator include roof trim and flashing?
No. Ridge caps, eave trim, rake trim, valleys, flashing, closures, underlayment, fasteners, sealants, ventilation, and disposal should be estimated separately.
Can every panel use the same length?
Simple rectangular roof planes often can. Hips, valleys, dormers, and irregular roofs may require a panel-by-panel cut list.
Common mistakes
- Using the full panel width instead of effective coverage width.
- Measuring horizontal run instead of sloped panel length.
- Ignoring eave, ridge, and field-cut allowances.
- Forgetting trim, flashing, underlayment, fasteners, and delivery.