Reference
Vinyl siding sizes: panel lengths, pieces per box and square feet in a square
Siding is quoted in squares, sold in boxes and installed in panels. The three units convert cleanly once you know the panel's face and length — which is what this page is for.
How many pieces of siding in a box? 24 panels of double 4 in vinyl, covering 200 sq ft — 2 squares. Double 4½ comes 22 to a box and double 5 20, for the same 200 sq ft. A square is 100 sq ft.
What is a square of siding
A square is 100 square feet of wall — a 10 by 10 ft patch — the same unit roofers use. Siding, trim, house wrap and labor are all priced per square. Measure the walls, subtract the doors and windows, add 10% for cuts, and divide by 100.
How many pieces of siding in a box: vinyl panel sizes
| Profile | Face | Panel length | Panels per box | Sq ft per box | Panels per square |
|---|---|---|---|---|---|
| Vinyl, double 4 in (8 in face) | 8 in | 12 ft 1 in | 24 panels | 200 sq ft (2 squares) | 12.4 |
| Vinyl, double 4½ in (9 in face) | 9 in | 12 ft 1 in | 22 panels | 200 sq ft (2 squares) | 11 |
| Vinyl, double 5 in (10 in face) | 10 in | 12 ft 1 in | 20 panels | 200 sq ft (2 squares) | 9.9 |
| Vinyl, dutch lap double 4½ in | 9 in | 12 ft 1 in | 22 panels | 200 sq ft (2 squares) | 11 |
Panels are nominally 12 ft; most brands cut them 12 ft 1 in so a 12 ft wall is one panel. Some lines run 12 ft 6 in or 16 ft — check the box, not the catalog.
Hardie board and LP SmartSide plank sizes
| Plank | Width | Exposure | Length | Planks per square |
|---|---|---|---|---|
| HardiePlank 6¼ in (5 in exposure) | 6.25 in | 5 in | 12 ft | 20 |
| HardiePlank 7¼ in (6 in exposure) | 7.25 in | 6 in | 12 ft | 16.7 |
| HardiePlank 8¼ in (7 in exposure) | 8.25 in | 7 in | 12 ft | 14.3 |
| LP SmartSide lap 8 in (6⅞ in exposure) | 8 in | 6.875 in | 16 ft | 10.9 |
| LP SmartSide lap 12 in (10⅞ in exposure) | 12 in | 10.875 in | 16 ft | 6.9 |
Fiber cement and engineered wood are sold by the plank, not the box; exposure is the width less the overlap — 1¼ in on Hardie, 1⅛ in on LP. They weigh far more than vinyl — about 2.3 lb per sq ft for Hardie — which matters for the delivery.
Trim and accessories per square
| Accessory | Per square | Sold as |
|---|---|---|
| J-channel | 15 ft | 12.5 ft lengths |
| Starter strip | the house perimeter, once — about 10 ft per square on a one-story | 12.5 ft lengths |
| Corner posts | one per outside corner per story | 10 ft lengths |
| Nails, galvanized roofing | 1 lb | 1 and 5 lb boxes |
J-channel goes around every window and door and under the eaves; the per-square figure is an average for a house with normal openings. Count the actual perimeter of openings if you can.
How many squares for a 2,000 sq ft house
| House | Gross wall area | Squares to buy |
|---|---|---|
| 1,200 sq ft ranch, one story | 1,260 sq ft | 14 |
| 2,000 sq ft two-story | 2,160 sq ft | 24 |
| 2,500 sq ft two-story with gables | 2,700 sq ft | 30 |
Gross wall area — doors and windows not taken off — with 10% waste, for a plain rectangle. Estimators usually leave small openings in to cover the extra cuts around them; a house with many corners and gables needs more. Floor area is a poor guide — two houses of 2,000 sq ft can differ by ten squares. The siding calculator works from the walls.
Work out your squares →Vinyl: CertainTeed, Ply Gem and Royal Building Products vinyl siding data and carton labels — double 4 in panels 12 ft 1 in long, 24 per carton covering 2 squares; double 4½ in, 22 per carton; double 5 in, 20 per carton; all 2 squares. J-channel, starter strip and nails per square are contractor estimating allowances; installation per the Vinyl Siding Institute (VSI) manual. Fiber cement: James Hardie HardiePlank product data — 12 ft planks in 6¼, 7¼ and 8¼ in widths at 5, 6 and 7 in exposure. Engineered wood: LP SmartSide lap siding contractor checklist — 16 ft planks, 8 in at 6⅞ in exposure, 11 pieces per square. Fiber cement and engineered wood pieces per square are 100 sq ft divided by the area one plank covers (exposure x length): HardiePlank 8 1/4 in at 7 in exposure covers 7 sq ft, 14.3 planks a square (Home Depot). Accessed 2026-10-23.
Siding size questions
How many square feet in a box of vinyl siding?
200 sq ft, or 2 squares, for every common profile; the panel count changes with the face width, the coverage does not.
How long is a piece of vinyl siding?
Nominally 12 ft; most brands cut 12 ft 1 in so a 12 ft wall is one panel. Some profiles come 16 ft.
How many pieces of Hardie board in a square?
14.3 of the 8¼ in plank, 20 of the 6¼ in, at 12 ft lengths.
How many squares of siding for a 1,500 sq ft house?
About 15–18 squares for a one-story rectangle with 9 ft walls and two gables; measure the walls — floor area only hints at it.
More in this series
The rest of the paint job
These charts are what every paint and exterior estimate on the site is built from: coverage, coats, drying times and the siding underneath. Each tool applies them to one surface.
- Paint Calculator Wall and ceiling paint, primer, rollers and tape
- Ceiling Paint Calculator Ceiling paint, stain-blocking primer, roller covers and tape
- Exterior Paint Calculator Gallons of exterior paint and primer by siding type, trim paint, rollers, brushes and tape
- Siding Calculator Squares of siding, panels and boxes of vinyl or planks of fiber cement, J-channel, starter strip, corner posts and nails
- Trim Paint Calculator Quarts of trim enamel and primer for baseboards, casing and crown by the linear foot, brushes, tape and caulk
- Cabinet Paint Calculator Quarts of cabinet enamel and primer for doors, drawers and frames, foam rollers, brushes and degreaser
- Fence Stain Calculator Gallons of stain or paint for both sides of a fence and its posts, by fence type and wood condition
- Primer Calculator Gallons of primer by surface and primer type, with the coats each surface needs, rollers and brushes
- Door Paint Calculator Quarts of enamel and primer for interior and front doors, one or both sides, with frames, brushes and foam rollers
- Paint Coverage per Gallon What a gallon covers on each surface, and gallons for common rooms
- Paint Sheen Chart Flat to gloss: durability, where each finish belongs, and the comparisons
- Paint Drying and Recoat Times Dry to the touch, recoat and cure times for latex, oil-based, primer, polyurethane and stain, and how weather changes them
- Spray Paint Drying Times Dry, handle, recoat and cure times for spray paint by type and surface, and how many cans a job takes
- How Many Coats of Paint and Primer Coats by color change and surface, how long to wait between coats, and coats of polyurethane and stain
- Primer Coats and Coverage How many coats of primer each surface needs, coverage per gallon by primer type, and how long each takes to dry
- Paint Can Sizes and Weights What a quart, gallon and 5 gallon bucket of paint weigh and how many square feet each one covers
Tools for the job
What makes this job easier
Tools and materials that suit this kind of job. These are affiliate links: if you buy through one, Renovimo may earn a commission at no extra cost to you. It never changes the figures on this page.
Garvee
Telescoping scaffold plank, 69–112 in
Spans two ladders for ceilings, crown and the top of the wall.
Check price
Garvee
Telescoping work platform
Spans two ladders or steps for ceilings, upper walls and stairwells.
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Garvee
Miter saw stand
Supports long trim, planks and boards at cutting height.
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Garvee
10 in table saw
Rips boards, treads and flooring to width.
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Garvee
Folding workbench, 4 × 2 ft
A cutting and mixing station that folds flat between jobs.
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Garvee
Cordless pressure washer
Cleans a deck or patio before stain or sealer goes on.
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Not the tool you were after? Browse the whole range at Garvee — the store these picks come from.