Residential shingles are measured and ordered by the roofing square, a standard unit of measurement used to determine the area to be covered. Roofing contractors use roofing squares to price materials, including shingles, underlayment, and water barriers, as well as their labor.
To calculate how many bundles of shingles you'll need for your project, you'll need to know how many bundles of shingles are in a square. With that information and the number of squares you need to cover your roof, you can quickly determine how many bundles you will need.
How many bundles of shingles are in a square?
For most standard asphalt shingles (3-tab and architectural), there are three bundles per square. A roofing square is equal to 100 square feet of roof area (10 ft x 10 ft).
There are some exceptions to the 3-bundles-per-square rule, as bundles are sized to make them easier to lift to the roof. So, check each package carefully to determine how much roof area it will cover. Some specialty shingles may require up to five bundles per square due to their added weight.
For example, GAF’s Timberline HDZ shingles comes three bundles to a square and 64 shingles per square. The Woodland line, on the other hand, comes four bundles per square and 56 shingles per square.
Quick reference table (roof size to bundles needed)
This quick-reference table lists the number of squares and bundles needed to cover several roof sizes. You can use it as a roofing material calculator to help you determine how many squares or bundles of shingles you'll need.
Note that the size of your roof will not equal the size of your home's footprint. Because of pitch, eaves, and other features, the size of your roof is usually larger than the square footage of your footprint. Make sure you measure the actual area of all roof faces before determining how much material you'll need.
The table assumes there are 3 bundles per square and does not include a waste or trim factor.
Roof Size (square feet) | Squares | Bundles |
1 000 | 10 | 30 |
1 500 | 15 | 45 |
2 000 | 20 | 60 |
2 500 | 25 | 75 |
3 000 | 30 | 90 |
How to calculate bundles for your roof
To answer the question, “How many bundles of shingles do I need?” use the following formula:
1. Calculate the total square footage of your roof by measuring the length and width of each plane of your roof, including dormers. Multiply the length by the width of each plane, then add the areas to get the total square footage of your roof.
For example, if you have a standard gable roof with two roof planes, each one 40 ft x 30 ft:
· Multiply 40 x 30 = 1 200 square feet
· 1 200 x 2 = 2 400 square feet
2. Determine the number of roofing squares required by dividing the total square feet by 100. (You'll want to add 10-15 % to the material total for trim allowance and waste.)
· 2 400 / 100 = 24 squares needed
3. Multiply the number of roofing squares needed by 3 (or the number of bundles per square) to determine the number of roofing bundles you’ll need.
· 24 squares x 3 = 72 bundles
If your roof has a steep slope or architectural features such as rakes, valleys, and dormers, you will need more material than the square footage would indicate. Your contractor will include additional material to cover these features. In addition, contractors will usually include a 10-15 % waste factor to help ensure they have enough shingles.
What is a roofing square?
A roofing "square" is an industry term for 100 square feet of roof area (10 ft x 10 ft). It helps contractors determine how much material they’ll need to order. If your roof requires 24 squares, that means it is approximately 2 400 square feet.
Roofers use this form of measurement to help simplify the estimating process. They perform a roof takeoff to determine the total square footage of surfaces to be covered, including dormers and multiple slopes, and then convert the total to roofing squares. It speeds up the estimating process, since materials and labor are priced per square as well.
Why are shingles sold in bundles instead of squares?
Roofing shingles are heavy and need to be lifted from the ground to the roof, often on a ladder. To help reduce the strain on workers from lifting heavy shingles, manufacturers package them in bundles.
While standard asphalt shingles require three bundles to cover a square, heavier shingles may be packaged in smaller bundles to facilitate lifting. All bundles are marked with their coverage area and indicate how many are needed to cover a square.
What to do next
The number of shingle bundles in a roofing square depends on the weight of the shingles. Standard 3-tab asphalt shingles come 3 bundles to a square, with a square covering 100 square feet of roof area. Check your shingle package or specifications to verify the coverage area.
For accurate material estimates, make sure you take precise measurements of your roof area, or hire a professional roofing contractor to help ensure everything is installed correctly.
