Siding Calculator

Whether you're installing vinyl, wood, or fiber cement siding, accurately estimating the amount of material required is the first step to a successful project. Our Siding Calculator helps you determine the total square footage needed, accounting for walls, gables, and areas that don't need siding, like windows and doors.

Key Steps in Siding Estimation

The process involves calculating the total surface area of your home's exterior walls and then subtracting the areas of any openings.

• Wall Area: The primary area of coverage, calculated for all rectangular wall sections.
• Gable Area: The triangular area at the top of a wall under a pitched roof.
• Non-Sided Areas: Openings such as windows, doors, and garage doors that must be subtracted from the total area.
• Waste Factor: An additional percentage of material (typically 10-15%) to account for cuts, scraps, and mistakes.

How to Measure Your House

1. Measure Walls: Measure the height and width of each rectangular wall section of your house. Add these sections to the calculator.
2. Measure Gables: For each gable, measure its width (base) and its height from the top of the wall to the roof peak (rise).
3. Measure Openings: Measure the height and width of every window, door, and garage door. Sum their areas to find the total area to be subtracted.

By breaking down your house into these simple shapes, you can achieve a highly accurate estimate.

Frequently Asked Questions (FAQ)

What is a typical waste factor for siding?

A 10% to 15% waste factor is standard. Use the higher end of the range for houses with complex shapes, many windows, or if you are less experienced with installation, as this provides a better buffer for cutting errors.

Do I really need to subtract the area of windows and doors?

Yes, for an accurate estimate. While some contractors use the material saved from these cutouts for the small areas above and below windows, it's better practice to calculate the gross area and subtract the openings. The waste factor will then properly account for the material needed for these detailed cuts.

Does this calculator estimate other materials like starter strips or trim?

No. This calculator is specifically for estimating the siding panels or planks (the field material). You will need to separately measure and calculate the linear feet needed for starter strips, J-channel, corner posts, and other trim pieces.