DIY Roofing Basics: How to Measure a Roof for Metal Panels

Measuring a roof for metal roofing does not have to be complicated. The goal is simply to determine how many panels you need and how long each panel should be.

Step 1: Measure the Roof Width

Measure the roof from eave to eave (side to side).

For example:

• Roof width = 34 feet

Convert feet to inches:

• 34 ft × 12 = 408 inches

Step 2: Divide by the Panel Coverage Width

Each metal roofing profile has a coverage width, which is the amount of roof one panel actually covers after the seams overlap.

Common examples:

• 1" Mechanical Lock Standing Seam = 17" coverage

• Corrugated Panel = 29" coverage

Mechanical Lock Example

408 in ÷ 17 in = 24 panels

Corrugated Example

408 in ÷ 29 in = 14.07

Always round up, so you would order 15 panels.

Step 3: Measure the Roof Length

Measure from the eave to the ridge (bottom edge to the top of the roof).



Example:

• Roof length = 18 feet

Your panel length would be approximately 18 linear feet (plus any desired overhang).

Step 4: Calculate Total Linear Footage

Multiply the number of panels by the panel length.

Mechanical Lock

• 24 panels × 18 ft = 432 linear feet

Corrugated

• 15 panels × 18 ft = 270 linear feet

This gives you the total amount of panel material needed.

Quick Formula

Number of Panels

Roof Width (inches) ÷ Panel Coverage Width (inches)

Panel Length

Roof Length (top to bottom) = Panel Length

Total Linear Footage

Number of Panels × Roof Length

A Few DIY Tips

• Measure each roof section separately if the roof has multiple planes.
• Round up on panel counts to avoid coming up short.
• Add a little extra material for waste, trimming, and future repairs.
• Remember that coverage width is not the same as the actual panel width—always use the manufacturer’s stated coverage width when calculating panel quantities.

With just roof width, roof length, and panel coverage width, most homeowners can get a solid estimate for ordering metal roofing panels before starting a DIY roofing project.

Now, if you're roof is this basic, you're pretty lucky. Usually we have flashing features like valleys, irregular hips, gable roofs or other architechtural features that could make things tricky. Just remember to apply the same principles in sections. Still have questions? Josh can steer you in the right direction. Call us 970-975-1712