Vinyl Siding Calculator

What Is a Square of Siding? A square is the standard unit for ordering siding, and it covers 100 square feet. All siding types (vinyl, wood, fiber cement, metal) are measured in squares. When ordering, always round up to the nearest square and add waste.

Vinyl Siding Basics Vinyl is the most common exterior cladding in North America. It arrived in the late 1950s in the United States as a low-maintenance answer to aluminum siding. Modern vinyl is UV-stabilized and impact-resistant, and lasts 20 to 40 years with no painting. It ships in 12-foot panels and is sold by its exposure, the visible height of each course once the panel above laps over it. Common exposures are 4 inches, 4.5 inches, 5 inches (Dutch lap) and 8 inches (a double 4 panel, which shows two 4-inch courses).

How Siding Is Installed Vinyl panels interlock rather than simply lapping: the bottom edge of each course hooks into the lip of the one below it. End-to-end joints overlap about 1 inch, which is why a wall consumes slightly more panel than its bare length suggests. Exposure is the number that drives coverage. A 12-foot panel with 8-inch exposure covers 12 × 8/12 = 8 square feet. The same panel at 4-inch exposure covers only 4. Starter strip runs the base of every wall. J-channel frames every window and door.

Ordering Tips Waste factor: 10% on simple rectangular walls, 15% once there are dormers, angles and a lot of cutting. Order 5 to 10 percent past that for future repairs. Colors get discontinued constantly, and a patch in the wrong shade is visible from the street forever. Accessories: J-channel around openings, F-channel under the soffit, starter strip at the base, and inside or outside corner posts. Corner posts come in 10-foot lengths, so each corner takes as many posts as its height divided by 10, rounded up.

Calculating Net Wall Area Gross area is the sum of all wall faces, each one length × height. Deduct the openings: a window is typically 15 sq ft, a door 20 to 21 sq ft, a garage door 64 to 120 sq ft. Gables are triangles, so their area is (base × height) / 2. Add them, do not deduct them. The tighter your opening measurements, the tighter the estimate. Most people overestimate window area and end up a square over, which is a cheap mistake to make.

Siding Profiles Dutch lap: most common residential profile. Has a distinctive curved top edge. Beaded lap: decorative bead at the bottom of each panel, for a traditional look. Board and batten: vertical orientation. Requires different installation and more waste. Shake/shingle: simulated wood shingle look. Higher cost but attractive. Panel siding (soffit): smooth horizontal panels used under eaves.

Cost Estimation Every figure below is an approximate national range that moves with grade, region, labor market and year, so price the job against your own quotes rather than these numbers. Vinyl siding material: $0.90 to $4.00 per sq ft depending on grade. Premium insulated vinyl: $2.50 to $5.50 per sq ft for the material. Installation labor: $1.50 to $4.00 per sq ft. Total installed: $3 to $10 per sq ft. A 2,000 sq ft house often works out to 15 to 20 squares. The calculator takes your own material and labor rates rather than assuming any of these.

A Note on the Accessory Estimates Starter strip and corner posts are worked out from the perimeter, which the calculator gets by dividing your gross wall area by the wall height you enter. That is why the height field matters even though the area fields already contain it: without a height there is no way to tell a 400 sq ft wall that is 40 ft long from one that is 100 ft long, and the starter strip figure differs by more than double between them.

J-channel is derived from the number of openings and their total area. It assumes each opening is roughly square, which for a 15 sq ft window gives about 15.5 linear feet of channel against the 16 feet a 3 by 5 window really takes. Close enough to order from, and 10% is added on top for the miters.