Free calculator
Roofing Square Calculator
Enter one or more roof-section areas to find your roofing squares -- the standard 100 ft² unit contractors and suppliers use -- with an optional waste/allowance percentage.
Calculate your roofing squares
Enter your roof section area(s) and waste/allowance above, then select "Calculate roofing squares" to see your results.
Accuracy & assumptions
What this calculator assumes
- Each section area you enter already reflects the actual roof surface you measured -- this tool does not measure your roof for you.
- Roofing squares are a measurement of area, not a purchase-unit count -- results are shown with full decimal precision, never rounded up to a whole number.
- Complex roofs with hips, valleys, dormers, or a steep pitch may need a higher waste/allowance percentage, and manufacturer requirements can affect how much material you actually order.
- This result does not replace an on-roof measurement or a supplier's own material take-off.
How to calculate roofing squares
How to use the roofing square calculator
- Enter the area of your first roof section, in square feet.
- Select "+ Add another section" for each additional, separately-measured roof plane (main roof, garage, porch, dormer, etc.).
- Enter a waste/allowance percentage for cuts, valleys, hips, and complex roof lines.
- Select "Calculate roofing squares" to see your results.
One roofing square, explained
What is one roofing square?
One roofing square equals exactly 100 square feet of roof area -- a standard unit the roofing industry uses instead of always citing raw square footage. A roof measuring 3,070 ft² is 30.7 roofing squares.
Roofing squares measure area, not a purchase quantity -- they are not the same thing as a shingle bundle. How many bundles cover one square depends on the specific shingle product, typically printed on the packaging. Once you know your roofing squares, use the Roofing Shingle Calculator to convert that into a bundle count for your chosen shingle.
Worked example
A worked example
Say a roof has three sections: 1,800 ft² on the main slopes, 850 ft² over the garage, and 420 ft² over the porch -- a total measured area of 3,070 ft² (30.7 roofing squares). Adding a 12% waste/allowance brings the adjusted area to 3,438.4 ft², which is 34.384 roofing squares.
FAQ
Frequently asked questions
How many roofing squares do I need?
Add up the measured area of every roof section in square feet, then divide by 100 -- that is your base roofing squares. This calculator does that math for you, and can also add a waste/allowance percentage to give you an adjusted total.
What is a roofing square?
A roofing square is a standard roofing-industry unit equal to 100 square feet of roof area. It lets contractors and suppliers talk about roof size without always citing raw square footage.
How do I calculate roof squares from square footage?
Divide the total roof area in square feet by 100. For example, 3,070 square feet is 30.7 roofing squares.
Do roofing squares include a waste allowance?
Not automatically -- a raw square-footage measurement only gives you the base squares. This calculator shows both the base roofing squares (your measured area alone) and the adjusted roofing squares (after adding your chosen waste/allowance percentage for cuts and complex roof lines).
Are roofing squares the same as shingle bundles?
No. A roofing square is a measurement of area (100 ft²), not a count of packages you buy. How many bundles cover one square depends on the specific shingle product -- use the Roofing Shingle Calculator to convert your roofing squares into a bundle count for a specific product.
Does this calculator save or store my numbers?
No. Everything runs in your browser and nothing you enter here is saved, sent to a server, or stored in any way -- reloading the page clears the form.
Next step
Already have your measurements? Turn them into a profitable estimate.
Roofing Estimate Pro helps contractors apply true material and labor costs, include overhead, price for a target margin, save estimates on this device, and produce a customer-ready proposal -- all from measurements you already have.
Build a profitable estimate