Metal roofing comes in exposed-fastener panels (corrugated or ribbed, 24–36 in coverage) and standing-seam panels (12–18 in). Panels usually run in one piece from eave to ridge, so the count depends on the length of the eave and the coverage width. Trim pieces – ridge cap, eave drip, rake/gable trim – add a significant amount.
How to use the Metal Roof Cost Calculator
- Eave length
- Rafter (slope) length
- Roof sides
- Panel coverage width
- Waste
- Panel price
- Labour price
- Trim price
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the eave length, the rafter (slope) length, the number of roof sides, panel coverage width, waste and prices for panels, labour and trim.
Tips for an accurate estimate
- Measure the footprint from the ground and apply the pitch multiplier rather than climbing on the roof.
- Add 10% waste for simple gable roofs and 15–20% for hips, valleys and dormers.
- Confirm design snow and wind loads with your local building department before changing framing or roofing.
- Always work with fall protection; roofing is one of the most dangerous trades.
Common mistakes to avoid
- Using the footprint area instead of the sloped roof area when ordering materials.
- Forgetting starter strips, ridge caps, drip edge and underlayment.
- Mixing up pitch (rise per 12 in of run) with the roof angle in degrees.
Inputs explained
| Field | What to enter |
|---|---|
| Eave length | Units: ft, m, in, yd, cm |
| Rafter (slope) length | Units: ft, m, in, yd, cm |
| Roof sides | Choose one: Gable (2 sides), Shed (1 side) |
| Panel coverage width | Choose one: 36 in (ribbed / corrugated), 24 in, 16 in standing seam, 12 in standing seam … |
| Waste | In % |
| Panel price | Units: /ft², /m², /yd² |
| Labour price | Units: /ft², /m², /yd² |
| Trim price | Units: /ft, /m, /yd |
What each result means
- Roof area = [Eave length]×[Rafter (slope) length]×[Roof sides]
- Squares = [Roof area]×(1 + [Waste]÷100)÷9.290304
- Panels = ceil([Eave length]÷[Panel coverage width] – 0.000001)×[Roof sides]
- Screws (≈ 80 per square) = ceil([Squares]×80)
- Panel cost = [Roof area]×(1 + [Waste]÷100)×[Panel price]
- Labour cost = [Roof area]×[Labour price]
- Trim cost = [Trim length]×[Trim price]
- Total cost = [Panel cost] + [Labour cost] + [Trim cost]
Example values
How the main result changes when Eave length changes and everything else stays at the example values above:
| Eave length (ft) | Panels |
|---|---|
| 20 | 14 |
| 30 | 20 |
| 40 | 28 |
| 50 | 34 |
| 60 | 40 |
| 80 | 54 |
Formula
Roof area = eave length × rafter length × sidesPanels per side = ceil(eave length ÷ panel coverage width)Trim = ridge + eaves + rakes; screws ≈ 80 per squareWorked example
Inputs — Eave length: 40 ft; Rafter (slope) length: 14 ft; Roof sides: Gable (2 sides); Panel coverage width: 36 in (ribbed / corrugated); Waste: 10 %; Panel price: $4 /ft²; Labour price: $3.5 /ft²; Trim price: $3 /ft.
Results — Roof area = 1,120 ft²; Squares = 12.32; Panels = 28; Panel length = 14 ft; Trim length = 176 ft; Screws (≈ 80 per square) = 986; Panel cost = $4,928.00; Labour cost = $3,920.00; Trim cost = $528.00; Total cost = $9,376.00.
Frequently asked questions
How much does a metal roof cost?
Roughly $8–$16 per ft² installed for exposed-fastener panels and $12–$20+ for standing seam in the U.S.; enter local prices for an estimate.
How many screws per metal roof panel?
About 80 per square (100 ft²) for exposed-fastener panels at 24 in purlin spacing.
Can metal roofing go over shingles?
Often yes, over one layer, with purlins or underlayment – check local code and the panel maker.
What formula does the Metal Roof Cost Calculator use?
Roof area = eave length × rafter length × sides.