How many bundles of shingles are in a square?

It depends on the shingle type. Standard 3-tab shingles use 3 bundles per square (100 sq ft). Architectural (dimensional) shingles use 3 bundles per square as well, though some brands require 4. Premium designer shingles often come 2 bundles per square. Always verify with your supplier's product data sheet.

What is a roofing square?

A roofing square equals 100 square feet of roof surface. Contractors and suppliers quote material quantities in squares. Knowing how many squares your roof has is the first step to ordering the right amount of shingles.

How do I measure roof pitch?

Pitch is expressed as rise over run, where run is always 12 inches. A 6/12 pitch rises 6 inches for every 12 inches of horizontal distance. You can measure it by holding a level against the roof and measuring the vertical distance from the 12-inch mark on the level down to the roof surface.

Why do I need a waste factor?

Shingles must be cut to fit around ridges, hips, valleys, rake edges, and eaves. These cut-offs cannot be reused on a full course. A 10% waste allowance covers most simple roofs. Add 15–20% for roofs with multiple dormers, skylights, or complex hip-and-valley intersections.

Does this calculator include ridge cap shingles?

No. Ridge cap shingles are a separate product sold by the bundle. As a rule of thumb, measure the total linear feet of ridge and hip lines and divide by 35 to get the number of ridge cap bundles needed.

What is the difference between 3-tab and architectural shingles?

3-tab shingles are flat and uniform in thickness — the original standard. Architectural (dimensional) shingles have a layered, textured look and are thicker, offering better wind and impact resistance. Both typically cover the same area per bundle, but architectural shingles last longer and cost more per bundle.

Shingle Calculator

Name: Shingle Calculator
Availability: InStock
Author: Nham Vu

Enter your roof footprint, pitch, and shingle type to get the exact bundle and square count you need to order.

Roof Dimensions

Building Length (ft)

Building Width (ft)

Roof Type

Roof Pitch (rise / 12)

/12

Common: 4/12 low, 6/12 medium, 9/12 steep

Shingle Type

3-Tab (Standard)

3 bundles / square — 33.3 sq ft per bundle

Architectural (Dimensional)

3 bundles / square — 33.3 sq ft per bundle

Premium / Designer

4 bundles / square — 25 sq ft per bundle

Waste Factor (%)

10% standard; 15–20% for complex roofs

Enter dimensions on the left to estimate shingles.

Summary

Enter your roof footprint, pitch, and shingle type to get the exact bundle and square count you need to order.

How it works

Enter the building footprint length and width in feet.
Select the roof type (gable, hip, or shed) and enter the pitch as rise/12.
Choose the shingle type — standard 3-tab, architectural, or premium — to set the coverage per bundle.
Set a waste factor (10% is standard; use 15–20% for complex roofs with dormers or multiple valleys).
The calculator applies the pitch multiplier to get true sloped area, then divides by coverage to give bundle and square counts.
Review the full breakdown including pitch angle, multiplier, and order quantities.

Use cases

Estimate material cost before requesting contractor quotes.
Verify a contractor's shingle order against your own calculation.
Plan a DIY re-roofing project with the correct quantity at the lumber yard.
Compare bundle counts across different shingle types (3-tab vs. architectural).
Account for complex roofs by adjusting the waste factor upward.
Convert a known roof area in squares directly to bundle counts.
Quickly check if leftover shingles from a prior job are sufficient for a repair.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu