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Free Roof Shingle Calculator

Use this roofing shingle calculator to estimate how many bundles of shingles you’ll need for a roofing job. Enter the roof’s floor area, eaves overhang, roof pitch, and the price of shingles to calculate the number of bundles required.

It’s a simple way to plan a job’s material needs and share quick estimates with your roofing customers.

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Disclaimer:

The outputs, any associated images or diagrams, any measurements, and any and all other information (collectively, the “Outputs”) are provided for informational purposes only and do not constitute a binding quote or professional advice. The Outputs are based on general assumptions and the information you provided, which may not reflect the actual specifications or condition of the subject of the calculation, particularly in the case of complex structures or inputs. Accuracy may also vary depending on location, as some data may be more complete in certain regions than others. Actual results or outcomes may vary significantly following an onsite inspection and detailed assessment by a qualified professional. Any auto-generated visuals are for illustrative purposes and may not accurately represent the subject of the calculation. The Outputs should not be relied upon as a final result or used as the sole basis for financial, renovation, operational, or strategic decisions. Jobber recommends consultation with a qualified professional before proceeding with any work, quotes, or financial decisions. Jobber and its affiliates make no warranties, express or implied, regarding the accuracy, completeness, or suitability of the Outputs, and to the fullest extent permitted by law, we disclaim all liability for any damages or losses arising from reliance on the Outputs.

How does this roofing shingle calculator work?

To calculate how many shingle bundles you need for a roof, along with the associated total cost, enter these details into our shingle calculator for a roof:

  • Floor area in square feet. For this example, let’s say you’re working on a 1,500-square-foot roof. You can plug that value into the calculator.
  • Eaves overhang (distance that the roof’s edge extends past the side walls) in feet. Assume that the roof you’re working on has a 1-foot overhang and enter that value into the calculator.
  • Roof pitch by degrees, percent, or fraction. We’ll use a fraction and assume a common pitch of 6/12. (You can select the “fraction” option from the dropdown in the calculator.)
  • Price of shingles per square foot. We’ll say $5 per square foot for this example, although this will vary depending on the type and quality of shingle you’re using.

Once you’ve entered your values, click “Calculate” to see your roofing shingles calculation. Given the values above, you can see that you’ll need 56 bundles of shingles, which will cost about $9,273.64.

This calculator helps you predict your approximate material costs when you’re pricing a roofing job, allowing you to give customers a fast ballpark estimate before a more detailed quote.


How do you calculate roof shingles in bundles?

Use this formula to figure out how many bundles of shingles you need for a roofing job:

Shingle bundles = (Roof square footage / 100) x 3

Say you’re building a new roof that measures 2,000 square feet. To calculate how many bundles of shingles you’ll need:

  1. Divide the roof’s square footage by 100 to get the total number of roofing squares (a unit that equals 100 square feet of roof surface). In this case, the roof is 20 squares.
  2. Multiply by 3, since three bundles typically cover one square. This means you’ll need 60 bundles to cover 20 squares of roof area.

It’s a good idea to include a waste factor of at least 10% to help cover areas like valleys and hips, as well as overlap and waste. In this example, the most accurate total is about 66 bundles of shingles.


How to calculate roof area using a shingle calculator

Our roof area calculator helps you find the total area of a roof by combining its length, width, and pitch. Here’s how:

  1. Add up the roof sections. If the roof has multiple sections, calculate the area of each section separately and add them up to get the total roof area.
  2. Measure the length and width of each roof plane from the ground or using building plans. Multiply these to find the base area. For example, a plane measuring 40 feet long by 30 feet wide would have a surface area of 1,200 square feet.
  3. Factor in the pitch of the roof (e.g., 4/12, 6/12, or 8/12), since a steeper roof means more surface to cover. Our roofing shingles calculator uses a pitch multiplier to adjust the roof area for you.


How to measure roof area

To find the total area of a roof, multiply length by width, then factor in the roof pitch. For example:

  • You’re building a roof with two equal planes, each measuring 35 feet by 30 feet. This means each plane has an area of 1,050 square feet.
  • Each plane has a pitch of 6/12. The standard multiplier for this pitch is about 12%. This brings the square footage of each roof plan to 1,176 square feet.
  • Add the roof planes together to get a total roof area of 2,352 square feet.

You can also use our roof surface area calculator to determine the size of a roof plane. For complex or irregular roofs, copy what we did here and break out the roof into sections. Measure one area at a time and add them all up to get your total roof area.

Frequently Asked Questions

A standard bundle could include anywhere from 15 to 29 shingles. The exact number of asphalt shingles in a bundle depends on the shingle type and brand. 

Most bundles include enough material to cover about 33.3 square feet of roof area. You’ll need three bundles to cover one roofing square (100 square feet).

Some types of shingles, like architectural shingles, are thicker and heavier than others. Although there might be fewer shingles per bundle, they’ll still cover approximately 33.3 square feet of roof.

Always check the manufacturer’s label for exact coverage before you order shingle bundles.
Use our roofing calculator to determine how many bundles of shingles you need. You can also calculate the number yourself by following these steps:

1. Calculate the roof area in square feet.
2. Divide the number by 100 to get the total number of roofing squares.
3. Multiply by 3 to get the number of shingle bundles needed.

You can also add an extra 10–15% waste factor, just to make sure you don’t run out of shingles. Round up to the nearest whole number—that’s how many bundles of shingles you need.
Here’s how to measure roof area when you’re quoting a roofing project:

1. First, find the area and pitch of each roof section.
2. Multiply the length and width of each section to get its area.
3. Adjust for roof pitch using a pitch multiplier.
4. Add all of the section area measurements together to get the total roof area.

Now that the roof is measured, use our roofing shingle calculator to figure out your shingle quantities and costs. Just enter the total area, eaves overhang, roof pitch, and bundle cost.
Follow these best practices to get an accurate shingle estimate and ensure you have enough roofing material:

• Use a roofing shingles calculator to create a rough estimate, then do more detailed calculations when it’s time to create your roofing quote.
• Measure each roof section separately. Factor in all planes (e.g., slopes, dormers, extensions) and account for overhangs and eaves.
• Use the correct pitch multiplier. Steeper roofs have a larger surface area, so use a roof shingle estimator that takes pitch into account.
• Add a waste factor of 10–15% extra. More complex roofs may need up to 20%.
• Round up to the next full bundle, as shingles are only sold in whole bundles.
• Check manufacturer coverage to make sure the customer’s specified shingle bundles will cover exactly 33.3 square feet each.
• Use consistent units (e.g., inches, feet, meters) throughout the calculation to avoid conversion errors.
• Double-check your measurements to make sure you don’t run out of materials.
A roof pitch multiplier tells you how steep a roof is. To calculate a roof pitch multiplier, use the roof’s rise and run to find how much extra surface area the slope adds compared to a flat surface. The formula is:

√(rise2 + run2) / run

Here’s an example with a 6/12 pitch, meaning it has 6 inches of rise (vertical height) for every 12 inches of run (horizontal length):

• Square the rise and run. 62 = 36 and 122 = 144.
• Add them together. 36 + 144 = 180.
• Take the square root. The square root of 180 is 13.416.
• Divide by the run. 13.416 ÷ 12 = 1.118 pitch multiplier.
Using a shingle bundle calculator offers several advantages for roofing contractors, like:

• Save time and effort calculating the roof area and the shingles needed
• Improve accuracy in roof pitch and bundle coverage calculations
• Order shingles in the correct quantities to avoid shortages and overages (and plan for other material needs, like underlayment, sealant, and roofing tools)
• Increase efficiency when you’re quickly estimating multiple roofing jobs