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How Many Soffit Panels and Fascia Boards Do You Need?

Enter your eave length and overhang depth to get the soffit panels and fascia boards to buy, with waste and full-piece rounding.

Last updated: July 26, 2026

Eave / Fascia Length (ft)

Add every roof edge where soffit and fascia will install.

Wall to fascia face. Common depths are 8–24 inches.

Soffit & Fascia Order Summary

14
soffit panels to buy
11
fascia boards to buy
Soffit Area 150 sq ft
Courses Across Overhang 1
Ordered Soffit Coverage 168 sq ft
Fascia Length + Waste 165 ft

150 ft eaves · 12" overhang · 12" × 12 ft panels · 16 ft fascia · 10% waste

Planning note

Vented soffit is commonly used for attic intake air, but this tool does not verify net free area. Order gutters, drip edge, and wall siding separately.

Worked Examples

Ranch eaves — 12 in overhang

150 ft eaves · 12 in overhang · 12 in × 12 ft panels · 16 ft fascia · 10% waste

Soffit panels14
Fascia boards11
Courses across1

One panel width covers a 12-inch overhang. Waste and full-piece rounding push the fascia order to 11 boards.

Same eaves — 18 in overhang

150 ft eaves · 18 in overhang · 12 in × 12 ft panels · 16 ft fascia · 10% waste

Soffit panels28
Fascia boards11
Courses across2

An 18-inch overhang needs two courses of 12-inch panels, so the soffit count doubles while fascia stays the same.

Vented vs Solid Soffit

Choose the panel style that matches the attic airflow plan, then order the piece count above.

Vented soffit

Use where you need intake air under the eaves. Pair it with ridge or other exhaust vents according to the product NFA and local code.

Solid soffit

Use on porch ceilings, closed overhangs, or sections that should not add intake openings. It finishes the look but does not replace a ventilation plan.

Common Panel and Board Sizes

Confirm what your supplier stocks before locking the order.

ItemUseful ForNote
8" soffit panelCommon for shallow overhangsOften paired with 12 ft panel lengths
12" soffit panelMost common retail widthOne course covers a 12 in overhang
16" soffit panelWider overhangs / fewer coursesCheck supplier stock before ordering
12 ft or 16 ft fasciaSold as full boards16 ft boards reduce piece count on long eaves

Frequently Asked Questions

Measure the total eave length where soffit will install, measure the overhang depth, then round up in both directions: how many panel widths cover the overhang, and how many panel lengths cover the eaves after waste. A common 12-inch by 12-foot panel covers one course across a 12-inch overhang.
Fascia usually follows the same eave length as the soffit run. Add any extra gable or rake fascia length, apply waste, divide by the board length you buy (often 12 or 16 feet), and round up to full boards.
Many homes use 12-inch-wide vinyl or aluminum panels in 12-foot lengths. 8-inch and 16-inch widths are also common. Match the panel width to your overhang, or plan multiple courses when the overhang is deeper than one panel.
Ten percent is a practical starting point for cuts, corners, and damaged pieces. Increase it for many hips, valleys, or short leftover runs. Full-piece rounding may already cover some of that cutting loss.
Use vented soffit where you need attic intake air, and solid soffit where ventilation is not wanted or already handled elsewhere. This calculator does not verify attic net free area; follow local code and the ventilation NFA listed on the product you buy.
No. Gutters and downspouts are a separate drainage order, drip edge belongs with the roofing package, and wall siding boxes are estimated on the siding calculator. This page only covers exterior soffit panels and fascia boards.

Related Calculators

Gutter CalculatorRoofing CalculatorRoof Pitch CalculatorSiding Calculator

References

  1. Angi — How Much Soffit Do I Need?
  2. Professional Calculators — Soffit Calculator
  3. Online Cost Calculator — Roof Soffit and Fascia Calculator