Free Calculator · By SubcontractorHub Editorial Team · Published November 2026
Soffit Calculator for Eave Area
A soffit calculator on this page is eave length times overhang depth. An 80 foot run at 16 inches is 106.667 square feet before waste. This page does not print a panel price, and it does not size the attic.
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Book a DemoHow the Soffit Calculator Measures an Eave
Width times length, then a second run only if you type one.
80 feet and 16 inches are the numbers in the boxes. They are not a house. Waste starts at zero. Panels stay blank until you type a coverage.
The first run is 106.667 square feet. No second run. Together before waste that is 106.667 square feet. No panel count, because no coverage was typed.
All calculations are estimates based on historical information and should be verified by the user.
Important: the depth is typed
All calculations are estimates based on historical information and should be verified by the user. This tool is provided as a free service for planning purposes only and is not a substitute for a professional assessment, a supplier quote, or applicable local code requirements.
This Soffit Calculator Is Not a Siding Price
CertainTeed's estimating page, fetched the day this was written, tells you to measure the width of the eave to be covered and the length of the eave, then multiply, and to repeat that for the remaining eaves. Porch ceiling is a separate line on that page: length times width. This soffit calculator uses the same product. The second pair of boxes is the rake, the porch, or the other eave. Leave them blank and they add nothing.
Wall siding is a different area. Vinyl takeoff lives on the vinyl siding cost calculator. A replacement scope that may include soffit is the siding replacement cost calculator. Equal board gaps on a wall are the board and batten calculator. None of those pages is this eave area.
Worked eave
Length 80 feet. Overhang 16 inches, which is 1.333 feet. The product is 106.667 square feet. Waste at zero leaves that number. Type 10 if you want the allowance CertainTeed describes for a large project. Type square feet per panel only from the carton in front of you. The soffit calculator will not invent a 12 foot panel.
| Line | Formula | Example |
|---|---|---|
| Depth in feet | inches ÷ 12 | 1.333 |
| First run | length × depth | 106.667 sq ft |
| Second run | typed, or zero | 0 |
| With waste | area × (1 + waste) | 106.667 at 0% |
How should you write the soffit order?
- Each eave length, in feet, walked, not scaled off a photo.
- Overhang depth from the wall to the fascia, in inches.
- A second run if the rake or the porch is also covered.
- Waste percent, labeled as typed. Ten is a choice, not a default.
- Square feet per panel from the product label, or no panel count.
- No price, and no vent count on this page.
What the Area Leaves Out
CertainTeed's Universal soffit product data, also fetched that day, names Triple 4 inch and Double 5 inch profiles. Fully vented Triple 4 prints 5.9 square inches of net free air. Center-vented Triple 4 prints 2.0 square inches. Fully vented Double 5 prints 6.4 square inches. The solid row's cell reads "Per Sq." This soffit calculator does not divide the attic by those figures, because the sheet does not give a sentence that says whether 5.9 is per panel or per square of soffit. Quoting the number is not the same as sizing a ridge.
Attic net free area, including the 1/300 and 1/150 split already on that tool, is the attic ventilation calculator. A roof walk that looks at soffit vents from the ground is the roofing inspection checklist. J-channel, F-channel, and fascia length are the eave length you already measured. This page does not add a corner allowance on top of the waste you type.
The product data says vented styles are for eaves, and that solid Triple 4 may also be used as vertical siding. A wall is not an eave. Do not send this square-foot number to a wall order. No price was on either CertainTeed page fetched today, so none is printed.
Frequently Asked Questions
How does the soffit calculator get square feet?
CertainTeed's estimating page says to measure the width of the eave and the length of the eave, then multiply. An 80 foot eave with a 16 inch overhang is 106.667 square feet before waste. A second run is added only if you type one. Waste stays at zero until you type a percent.
Does this soffit calculator count panels?
Only if you type square feet per panel. No panel coverage was taken from a catalog as a default. CertainTeed's Universal soffit product data names Triple 4 and Double 5 profiles and does not print a square-foot coverage this page will use as a default.
Is 10 percent waste required?
No. CertainTeed's estimating note says that on a large project you may want to add a 10 percent waste allowance for siding, soffit, and accessories. The waste box starts empty so this soffit calculator does not add 10 unless you type it.
Does this size attic vents?
No. CertainTeed's Universal soffit sheet prints net free air for vented profiles. This page quotes those figures and does not turn them into a vent count. Attic net free area is the attic ventilation calculator.
Measure the Eave, Then Price the Panel Elsewhere
Square feet are a rectangle. Dollars are a supplier.
Get a Free DemoAll calculations are estimates based on historical information and should be verified by the user. This tool is provided as a free service for planning purposes only and is not a substitute for a professional assessment, a supplier quote, or applicable local code requirements.