Soffit & Fascia Calculator — Sq Ft, Boxes & Lineal Feet
Estimate soffit and fascia for your roofline in one pass. Enter each eave and rake run, set the overhang depth, and get soffit square footage, squares, and boxes plus fascia lineal feet and pieces — with a downloadable takeoff PDF.
| Run | Length | Soffit ft² | Fascia ft |
|---|---|---|---|
| Run the calculator to see your takeoff | |||
How to use the soffit & fascia calculator
Four quick steps turn your roofline into soffit square footage and boxes plus fascia lineal feet and pieces — all in one pass, with a downloadable takeoff.
Set material & sizes
Choose vinyl or aluminum, then the overhang depth, fascia face, soffit box coverage, and stock length.
Add your roofline runs
Enter each eave and rake by length, with a quantity for matching sides. Eaves get soffit + fascia; rakes get fascia.
Add a waste factor
Dial in waste for the miters and corners — 10% is typical, more for cut-up rooflines.
Read results & save a PDF
Get soffit area, squares, and boxes plus fascia feet and pieces, with a run-by-run breakdown and PDF.
How a soffit & fascia takeoff is calculated
Two measures, worked side by side: soffit is an area (run × depth) and fascia is a length (feet along the edge). Here is the exact math the calculator runs.
Worked example — two eaves (40 ft) + two rakes (24 ft), 16″ overhang, vinyl, 10% waste
Soffit (eaves only): 80 ft × (16/12) = 107 ft² → +10% = 117 ft²
Soffit boxes (200 ft²/box): 117 / 200 → 1 box (≈ 1.2 squares)
Fascia (eaves + rakes): 80 + 48 = 128 ft → +10% = 141 ft
Fascia pieces (12 ft): 141 / 12 → 12 pieces
Order 1 soffit box + 12 fascia pieces — 13 pieces in all.
Soffit & fascia estimating charts
Handy lookups for what each run type covers, soffit area by overhang depth, fascia pieces by run, and common sizes. Coverage and profile vary by brand — check your product’s label.
| Run type | Soffit | Fascia | Where |
|---|---|---|---|
| Eave | Yes | Yes | Horizontal overhang |
| Rake | — | Yes | Sloped gable edge |
| Soffit only | Yes | — | Porch ceilings, boxed rakes |
| Fascia only | — | Yes | Where soffit is already done |
Soffit area comes only from soffit runs; fascia lineal feet comes from every fascia run. Rakes are fascia-only by default.
| Overhang depth | Soffit area | Squares |
|---|---|---|
| 12 in | 100 ft² | 1.0 sq |
| 16 in | 133 ft² | 1.33 sq |
| 18 in | 150 ft² | 1.5 sq |
| 24 in | 200 ft² | 2.0 sq |
Area = eave run × (depth ÷ 12). Scale for your eave run: a 24″ overhang over 40 ft of eave is 80 ft² of soffit.
| Fascia run | With 10% waste | 12 ft pieces | 16 ft pieces |
|---|---|---|---|
| 50 ft | 55 ft | 5 pieces | 4 pieces |
| 100 ft | 110 ft | 10 pieces | 7 pieces |
| 150 ft | 165 ft | 14 pieces | 11 pieces |
| 200 ft | 220 ft | 19 pieces | 14 pieces |
| 300 ft | 330 ft | 28 pieces | 21 pieces |
Pieces round up. Longer stock means fewer pieces and fewer end joints on long straight runs.
| Element | Typical |
|---|---|
| Overhang depth | 12–24 in (16 in common) |
| Fascia face | 6 in (2×6) or 8 in (2×8) |
| Soffit box coverage | ~200 ft² (varies by brand) |
| Stock length | 12 ft common (10 / 16 ft also) |
Match the fascia face to your sub-fascia board. Always confirm coverage and profile against your product’s label.
Everything the calculator works out
One set of roofline runs gives you every number needed to order both trades at once — soffit by the box and fascia by the piece.
Key figures every roofline takeoff depends on
Built for any eave job
From wrapping one house’s eaves to a full exterior package, the same calculator handles both trades at once.
Re-doing tired soffit and fascia and wants the boxes and pieces to buy without over-ordering.
- Enter each eave and rake length
- Set your overhang depth
- Get boxes + fascia pieces
Pricing soffit and fascia across the whole roofline with eaves and rakes counted correctly.
- Batch matching sides with Qty
- Split vented vs solid soffit runs
- Hand the PDF takeoff to the yard
Adding eave work to a re-roof and rolling soffit and fascia into one material list.
- Total soffit squares & boxes
- Convert fascia feet to pieces
- Order trim & channels separately
7 tips for an accurate eave order
Soffit and fascia meet at every corner, so a clean takeoff — and the right accessories — makes the install go smoothly. These habits keep your count honest.
Soffit & fascia calculator FAQ
The measuring, coverage, and ordering questions people ask most before buying soffit and fascia.
They’re measured two ways. Soffit is an area: total eave run × overhang depth. Fascia is a length: lineal feet along eaves and rakes.
For soffit, multiply eave run by the overhang depth in feet, then divide by 100 for squares or your box coverage for boxes. For fascia, add up every eave and rake and divide by stock length. Add ~10% waste to both.
Example: 80 ft of eave at a 16″ overhang ≈ 107 ft² of soffit (about 1 box), and 128 ft of fascia ≈ 12 twelve-foot pieces.
Fascia is the vertical board that caps the ends of the rafters along the roof edge — it’s what gutters usually attach to. Soffit is the horizontal underside of the overhang, between the fascia and the wall.
Because of those shapes, they’re estimated differently: soffit by square footage (a surface you cover) and fascia by lineal foot (an edge you wrap).
This calculator handles both at once from your roofline runs.
By area. Soffit covers the flat underside of the overhang, so you need square feet, not just a length.
The area is the eave run (the horizontal length) × the overhang depth (how far the eave projects). A 40 ft eave with a 16″ (1.33 ft) overhang = 40 × 1.33 ≈ 53 ft².
Convert to squares by dividing by 100, or to boxes by dividing by the coverage per box and rounding up.
Fascia is measured in lineal feet along the roof edge. Add up the run of every eave (horizontal edges) and every rake (sloped gable edges), then divide by stock length and round up.
Measure rakes along the slope, not the flat span, since fascia follows the roofline. Match the fascia face to your sub-fascia — a 2×6 takes about a 6″ face, a 2×8 about 8″.
Add a waste factor for the miters at each corner.
Usually not. A rake is the sloped edge of a gable, and on most homes it gets fascia (and sometimes a rake board) but no soffit — there’s no horizontal overhang to enclose.
That’s why the calculator treats a Rake run as fascia only and an Eave run as both soffit and fascia.
If your design has a boxed or overhanging rake with an enclosed underside, add that portion as a separate Soffit only run for its area.
Most residential overhangs run 12 to 24 inches, with 16 inches common. The overhang depth is also the width of the soffit, so it drives the soffit area directly.
Deeper overhangs shade windows and keep water off the walls, but use more material — going from a 12″ to a 24″ overhang doubles the soffit square footage for the same eave run.
Measure from the wall face out to the back of the fascia to get the true depth.
Not the quantity — vented and solid soffit cover the same area, so the square footage and box count are the same either way.
What changes is which product you order. Attics need intake ventilation, and vented soffit provides it, often paired with a ridge vent. Many jobs mix vented and solid, so split those into separate runs if you want each count.
The airflow requirement itself is a code and performance matter — confirm your net free vent area separately from the material takeoff.
A 10% waste factor is typical. Increase it to 15% or more for cut-up rooflines with lots of corners, returns, dormers, or short runs.
Waste covers the miter cuts at every inside and outside corner, offcuts too short to reuse, and the occasional damaged piece. Fascia has a mitered joint at each corner, so corner-heavy rooflines eat more material.
Rounding up is cheap insurance against a second trip to the supplier.
Estimating Notice: Actual soffit and fascia quantities vary with roofline layout, overhang depth, panel coverage, profile, and how eaves, rakes, and corners are handled. This calculator provides area- and length-based counts from your input — coverage per box, exposure, and stock lengths differ by brand, so always check your product’s label. Trim, F-channel, J-channel, corner posts, fasteners, and ventilation components are not included and must be ordered separately, and attic ventilation requirements should be confirmed against your local code. Verify all quantities with your supplier before ordering. For planning purposes only.