CrewMeasure

Soffit and Fascia Calculator

Soffit panel count plus F-channel, J-channel, and fascia board linear footage.

You'll need — soffit panels and — ft of fascia.

Roof data source

Pull soffit area and eave length from the roof calculator, or override manually.

Area source

Ran the Roof calculator already (with an overhang entered)? Keep Active project selected. Otherwise switch to Manual and type your own values.

Chained roof data

Run the roof calculator first (with an overhang entered) to prefill soffit area and eave length.

Soffit and fascia inputs

Panel type, panel width, and waste percent.

Panel type

Vented panels have small perforations for attic airflow; solid panels don't. Check your attic ventilation plan if unsure.

You'll need — soffit panels and — ft of fascia.

You'll need

Soffit and fascia estimate

Warnings

  • ERROR Enter a soffit area greater than zero.
  • ERROR Enter a fascia/eave length greater than zero.
  • INFO No soffit/fascia data is saved in the active project yet, so manual values are being used.

Detail values

Soffit area used
— sq ft
Eave length used
— ft

Assumptions

  • Panel width: 1 ft (12 in) x 12 ft long
  • Panel type: Vented
  • Estimated waste: 10% for an average project
  • Panel-length drop: Not modelled -- panels are sold 12 ft long and cut to fit the overhang, and the offcut left on each one is expected to be covered by the waste percent above

Included: soffit panels, F-channel, J-channel, fascia board.

Not included: labor, delivery, permits, disposal of waste material.

Formula details
  • Panel count: ceil((soffitArea x (1 + waste)) / (panelWidth x 12))

    Standard soffit panels are sold 12 ft long; coverage per panel is panelWidth x 12 sq ft. That is the nominal area of a panel and carries no cut allowance -- the drop left on each 12 ft panel once it is cut to fit the overhang is not modelled here, and the waste percent is expected to cover it. Where it does not, the count is short rather than long.

  • Channel length: fasciaLength x (1 + waste)

    F-channel at the wall, J-channel at the fascia and the fascia board itself all run the full eave length -- the soffit panel spans between the two channels. The ordinary installation convention, not a published schedule.

Material List

About this calculator

Pull soffit area and eave length from the active project's roof result, or override manually.

FAQ

Can I use this without the roof calculator?

Yes. Switch to manual values and enter soffit area and eave length directly.

What panel width should I use?

Standard vinyl/aluminum soffit panels are commonly 12 in (1 ft) or 16 in (1.33 ft) wide by 12 ft long -- enter whichever matches your product; the default is 12 in.

What's the difference between F-channel and J-channel?

F-channel attaches at the house wall and J-channel at the fascia board; both run the full eave length and the soffit panel spans between them.