Vinyl Siding Panel Calculator
Turn your net wall area into a count of vinyl siding panels and cartons. Set the panel exposure and length — the coverage per panel follows from those — add waste, and the tool rounds up to whole panels and boxes.
Calculator
At 8 in exposure on 12 ft panels (8.0 sq ft each), 1,230 sq ft plus 10% waste is 170 panels ≈ 8 cartons (panels/carton varies — check your product).
Vinyl siding is bought by the panel and by the carton, so once you know how much wall you have to cover, the count comes down to how much finished face each panel shows. That is set by the exposure — the height of wall a single course covers — and the panel length.
A “double-4” panel shows two 4-inch courses, an 8-inch exposure; a “double-5” shows two 5-inch courses, a 10-inch exposure. Multiply the exposure (in feet) by the panel length and you have the square feet each panel covers. Divide your net area (plus waste) by that, round up, and group into cartons.
Formula
Coverage per panel, then panels, then cartons:
panel coverage = (exposure ÷ 12) × panel length (sq ft)
panels = ⌈ net × (1 + waste %) ÷ panel coverage ⌉
cartons = ⌈ panels ÷ panels per carton ⌉
The ⌈ ⌉ brackets mean “round up to the next whole” — you cannot buy a fraction of a panel or a carton.
Worked example
For 1,230 sq ft of net wall, double-4 panels (8 in exposure) that are 12 ft long, 24 panels per carton, at 10% waste:
- Coverage: (8 ÷ 12) × 12 = 8 sq ft per panel.
- With waste: 1,230 × 1.10 = 1,353 sq ft to cover.
- Panels: 1,353 ÷ 8 = 169.1 → 170 panels.
- Cartons: 170 ÷ 24 = 7.1 → 8 cartons.
Going from double-4 to double-5 (10 in exposure) raises coverage to 10 sq ft per panel and drops the count — wider exposure means fewer panels.
Exposure, cartons & trim
Exposure is the single biggest lever on the panel count. A double-5 course covers 25% more wall than a double-4, so the same house needs proportionally fewer panels — but the square-footage of wall does not change, only how it is divided up.
Cartons vary. The number of panels per carton is a product detail, not a constant. Two-square cartons are common, but boxes run anywhere from about 16 to 24 panels depending on the profile and manufacturer. Enter the figure printed on your box so the carton count matches what you will actually buy.
Starter, corners and trim are separate. This tool counts field panels — the siding that covers the flat wall. Starter strip, J-channel, inside and outside corner posts, utility trim and finish trim are ordered by the linear foot of the run they follow, not by wall area. Budget those from your corner and opening perimeters.
Buy the dye lot together. Vinyl color can shift slightly between production runs, so order all the field cartons at once and keep a spare panel or two for future repairs.
Reference table
| Panel exposure | 10 ft panel | 12 ft panel | 16 ft panel |
|---|---|---|---|
| Double-4 (8 in exposure) | 6.67 sq ft | 8.00 sq ft | 10.67 sq ft |
| Double-5 (10 in exposure) | 8.33 sq ft | 10.00 sq ft | 13.33 sq ft |
Coverage per panel = (exposure ÷ 12) × panel length. Divide your net wall area (with waste) by this to get panels.
Frequently asked questions
How many vinyl panels are in a carton?
It varies by product — often around 24 panels, roughly two squares of coverage, but anywhere from about 16 to 24 depending on the profile and brand. Enter the number printed on your box so the carton count is accurate for what you buy.
What is the difference between double-4 and double-5 siding?
They describe the exposure. Double-4 shows two 4-inch courses for an 8-inch exposed face; double-5 shows two 5-inch courses for a 10-inch face. Double-5 covers more wall per panel, so you need fewer panels, though the total wall area is unchanged.
How do I convert square feet to vinyl panels?
First find the coverage of one panel: exposure in feet times panel length. Then divide your net wall area (with waste added) by that coverage and round up. For 8-in exposure, 12-ft panels that is 8 sq ft each, so 1,353 sq ft needs 170 panels.
How long is a vinyl siding panel?
Most vinyl panels are about 12 ft long, though 16-ft and other lengths exist. Longer panels mean fewer end laps on long walls; enter your actual panel length so the coverage per panel is correct.
Does the tool include corner posts and trim?
No — it counts field panels only. Starter strip, J-channel, corner posts and finish trim are ordered by the linear foot of the runs they follow, so estimate those separately from your corner and opening measurements.