SettingsSettings for this calculationUS
The standard allowance most suppliers and estimating guides assume for ordinary work.
The total length of roofline needing soffit.
Measure along each eave that will be soffited, and add them together.
Tools needed: Tape measure or measuring wheel, Ladder
The horizontal depth of the roof overhang.
Measure from the wall face to the outer edge of the fascia — this is how wide the soffit strip needs to be.
Panel lost to rip cuts, corner returns and cut-outs for vents and lights.
A deep overhang ripped from full-length panels leaves a strip on every one, and each boxed corner return is cut from its own piece. A long straight eave with square ends manages on less than ten; a run broken up by corners, porch returns and cut-outs needs more.
Soffit material needed
7 x 12 sq ft panels
- Overhang area (with waste)
- 80.85 sq ft
They open the calculator with your figures already in it
Soffit Panel Calculator: 7 x 12 sq ft panels — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Standard vented vinyl/aluminum soffit panel in North America is 12 in wide x 12 ft long (12 sq ft); panel count = overhang area / 12, rounded up with a waste allowance. Metric markets sell soffit as board in a range of widths rather than in one fixed panel size, so the metric answer is reported as an area of board
Inputs used
- Total Eave Length
- 49 ft
- Overhang Width
- 18 in
- Waste Allowance (%)
- 10
Intermediate steps
- Overhang area (with waste)
- 80.85 sq ft
What this calculation does not cover
- The area is a single rectangle - your total eave length multiplied by one overhang width - so a porch or bay that projects further than the rest of the roof, and the boxed return where two eaves meet at a corner, have to be run through separately and the results added.
- Overhang width is read as the horizontal distance from the wall face out to the fascia, so an open soffit that follows the rafter tails up to the roof deck spans further than the figure entered and the material will come up short.
- Waste is one percentage of the area, so the same setting is generous on one long straight eave with square ends and thin once the run is broken up by corners, rip cuts and cut-outs; set it to suit the run.
- Panels are counted by dividing that area by 12 sq ft (1.1 m²), which assumes every offcut from a 12 ft length gets used somewhere; an overhang depth that does not divide evenly into 12 ft leaves a short end on each panel, and whether the flat tenth absorbs it depends on the depth you are cutting to.
- The 12 in by 12 ft panel is written in as a constant, so a supplier profile in another width or length cannot be entered and the count returned will not be the count you order.
- The imperial answer is rounded up to whole panels, while the metric one is a plain area with the waste already inside it - it has had no rounding applied at all, so round it up again to the board lengths your merchant actually stocks.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Part of a bigger job
This trade is one line of a job takeoff. Run the whole job and every other trade comes back with it, off the same measurements.
also measuresFascia BoardGutterGutter Hanger SpacingGutter Guard
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-17 · v1.1.0
Regulatory standards & verification citations1
- Standard vented vinyl/aluminum soffit panel in North America is 12 in wide x 12 ft long (12 sq ft); panel count = overhang area / 12, rounded up with a waste allowance. Metric markets sell soffit as board in a range of widths rather than in one fixed panel size, so the metric answer is reported as an area of board
Cite this page
Your workspace
Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.
Tools and safety for this job
To fix roof sheeting and soffit panels and hang siding or cladding. Generic types, no brands, no prices.
Protection this work requires
- Hardwood dust is a recognised carcinogen: extract at the tool and wear a P2/N95 respirator when cutting or sanding indoors.
- Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
- Most fatal falls on small jobs are from under three metres: use a tower or a ladder tied at the top, and never work off the top two rungs.
- Knives cause more site injuries than any power tool: cut away from your body, change blades often, and wear cut-resistant gloves to EN 388 level C for repeated cutting.
Fix roof sheeting and soffit panels: Roof work is the commonest cause of serious fall injury on domestic sites, and profiled sheeting adds a danger of its own: older fibre-cement and plastic sheets, and the rooflights set among them, can give way under a person's weight without warning. Edge protection or a properly erected tower is the equipment that matters most here, and a roof that is fragile, steep, high or wet is a job for a roofer with the right access and staging, not a longer ladder.
Show the 10 tools this job needsHide tools
Essential
Chalk line
Circular saw
Cordless drill/driver
Extension ladder
Impact driver
Metal snips
Spirit level
Tape measure
Tower scaffold or trestles
Recommended
Mitre saw
Also needed as materials: chalk refill, circular saw blades, drill and driver bits, impact driver bits, mitre saw blades.
what each roofing tool is for and what each cladding tool is for, and the spec that decides which to buy where one does.