Free metal roofing calculator: panels, screws, strapping and trim
Get the panels, the length to order, the screws and the trim of a metal roof in seconds, free and without an account. One row per roof plane: its eave length, its top edge (the ridge, 0 for a hip end), the slope length from eave to ridge and how many ends are cut on a slope. Add the panel's coverage width and your fastening and strapping figures: the calculation gives the panels, the panel length to order, the screws, the strapping, the underlayment rolls, and one kind of trim's pieces and screws. In imperial or metric.
Metal panels: what the data sheets say (reference)
Figures read in the makers' data sheets and installation guides, one product each. Your panel's have the last word.
| What the data sheet says | |
|---|---|
| Westman Steel Tough Rib | 36 in (914 mm) coverage, minimum 3:12; sheets 1 to 2 in past the eave; at least three fasteners per 10 ft 6 in of eave trim |
| Metal Sales PBR | 36 in coverage, minimum 1:12; lengths 5 to 45 ft recommended |
| ABC 5V Crimp | 24 in coverage, minimum 3:12; at the ridge, a row of fasteners 1 ft on center |
| Vicwest Regency | 16 in (406 mm) coverage, 3:12 or more; screws every 16 in along the fastening track, over plywood at least 1/2 in; flashings 10 ft long |
| Vicwest Tradition 100 | 15.75 in (400 mm) coverage, minimum 3:12, lengths 4 to 40 ft |
| Vicwest TSR System 1000 | A standing seam on clips, 610 mm wide, recommended down to 1/4:12 |
| Fabral (estimating) | 4.5, 3.0 and 2.5 screws per linear foot of roofing for rows 12, 18 and 24 in apart; trims in 10 ft 6 in sections lapped 6 in; trim screws per foot: eave 1, gable 2, valley 3, ridge 2.67, hip 4, sidewall 2, endwall 1 |
| McElroy Multi-Rib | Trim pieces lapped 2 in, with butyl sealant in the laps |
| Underlayment rolls | Synthetic: commonly 10 squares (48 in x 250 ft); No. 15 felt: about 4 squares |
Sources: Westman Steel, Tough Rib; Metal Sales, PBR Panel; ABC, 5V Crimp; Vicwest, Regency; Vicwest, Tradition 100; Vicwest, TSR System 1000; Fabral, Grandrib 3; McElroy Metal, Multi-Rib; Makers' data, underlayment rolls
How it is calculated
Area = (eave + top edge) / 2 x slope length. Panels: the full-length panels across the shorter edge (short edge x 12 / coverage width, rounded up), plus on each sloped end its run (the difference between the two edges, shared between the sloped ends) x 12 / coverage width, rounded up. Length to order: each panel at its long edge, as Fabral orders hip and valley panels: from the full slope length, each next panel shorter by slope length x coverage width / the end's run, plus the overhang on every panel. Screws = length to order x screws per foot. Strapping = (slope length x 12 / spacing, rounded up, + 1) rows x the plane's average width. Rolls = area / roll coverage. Trim pieces = trim run / (piece length - lap), screws = run x screws per foot. Screws, rolls and pieces are rounded up once on the total. The same formulas as the metal roofing survey template; every size and rate is yours, from your panel's data sheet.
Example: a hip roof, panels ordered at their long edge
From our template page's demo: a 42 x 30 ft house at 6/12 with a hip roof. Two trapezoid planes run 42 ft at the eave and 12 ft at the ridge, two hip-end triangles 30 ft at the eave and 0 at the top, all 16.75 ft from eave to ridge, each with 2 ends cut on a slope. With a 36 in ribbed panel, a 1.5 in overhang, 3 screws per foot, strapping every 24 in and 1,000 sq ft underlayment rolls, the roof is 1,407 sq ft: 48 panels, 542 ft of panels to order, 1,626 screws, 840 ft of strapping and 2 rolls. The area divided by the 3 ft coverage would give only about 475 ft: on a hip, each panel is cut from a sheet ordered at its long edge, as Fabral orders hip panels. For 144 ft of eave trim in 10.5 ft pieces lapped 2 in, at 1 screw per foot: 14 pieces and 144 screws.
The whole job in MesuPro
Metal roofing survey
Metal roofs plane by plane: panels from the coverage width, length to order, screws, strapping, snow guards, trims and flashings.
You get: Area Panels Panel length to order
Your trade isn't listed? The AI assistant builds your form.
Start your 14-day free trialNo credit card. Cancel anytime.