Roof Square Footage Calculator
Need to know your roof size? Enter your home’s footprint and roof pitch in the calculator below to work out roof area, roofing squares and shingle bundles. Or skip the tape measure and measure from your address by satellite.
Calculate your roof square footage
Enter the footprint and pitch to get roof area, squares and shingle bundles.
Asphalt shingles aren’t used on roofs flatter than 2/12, so no bundle count is shown for this pitch.
Bundles assume 3 per square, typical for asphalt shingles; check the coverage printed on the product you choose. Dormers, multiple pitches and detached structures change the total, and a contractor measures before ordering.
Measure a roof by addressEnter the property address in the next tool. Satellite coverage varies, and an email is required for the free report.
Turn this into a materials and budget worksheet
Quantities come from the roof area above. Lengths and prices are yours: BuildFolio supplies no prices, and a line without a price stays out of the total. Print it or download it to take to a supplier or compare with a quote.
Add a price to any line to start a total.
Some entries were left out. Use plain numbers from 0 up, and more than 0 for bundles per square and roll coverage.
These are planning figures from your inputs, not a quote. Check the coverage printed on each product, allow for overlaps and cuts on the lengths you measured, and have a contractor measure before ordering.
Contractor? Carry these quantities into the roofing estimate template. Homeowner with a quote in hand? Check it with Is My Quote Fair?
Quick Answer
Roof area is the footprint the roof covers times a pitch multiplier, not the living space. A 1,500 sq ft footprint with a 6/12 pitch has about 1,677 sq ft of roof (16.8 squares) before overhang and waste. Work out your own above, or the easiest way to measure it is with our free roof report – enter your address and get satellite-measured results in 60 seconds.
How to Calculate Roof Square Footage
Method 1: Satellite (Easiest)
Our free roof report tool uses aerial imagery to calculate your roof’s square footage automatically. Just enter your address – no measuring, no climbing.
Enter your address
Type your street address into the tool
We analyze satellite data
Our system identifies your roof and measures each section
Get your report
Total sq ft, individual sections, pitch, and more
Method 2: Manual Calculation
If you prefer to measure yourself, you’ll need to account for both the footprint and the pitch. The calculator above does the math for you.
The Formula
Roof Area = Footprint Area × Pitch Factor
Example: A 1,500 sq ft footprint with a 6/12 pitch (1.12 factor) = 1,680 sq ft roof area.
Pitch factors
4/12 = 1.054 | 6/12 = 1.118 | 8/12 = 1.202 | 10/12 = 1.302 | 12/12 = 1.414
Why Knowing Your Roof Size Matters
Compare Quotes Accurately
When contractors quote different square footages, someone’s wrong. Know your actual size so you can spot overestimates that inflate your bill.
Budget for Materials
Roofing materials are priced per “square” (100 sq ft). Knowing your roof size helps you estimate material costs before talking to contractors.
Insurance Claims
Insurance adjusters measure your roof to estimate claims. Having your own measurements helps ensure you’re compensated fairly.
The 5% rule
Measurements differ between methods, and a difference is not by itself evidence of a problem. If a quote’s square footage is far from what you expected, ask the contractor how they measured and what they included — waste factor, overhangs, and attached structures all move the number legitimately.
Get Your Roof Size – Free
Enter your address and get satellite-measured square footage in 60 seconds.
Calculate NowMore free tools for your home: Free Roof Estimate by Address · How Many Solar Panels Fit on My Roof? · Storm & Hail Report · Property Report
Frequently Asked Questions
What’s the average roof size for a house?
No single average is worth planning around, because roof area follows the footprint and pitch rather than the living space. A one-story home with a 1,500 sq ft footprint has about 1,677 sq ft of roof at a 6/12 pitch and about 2,121 sq ft at 12/12. A two-story home with the same living space sits on roughly half that footprint, so its roof is much smaller. Measure your footprint and use the calculator above.
Is roof square footage the same as house square footage?
No. Roof square footage is usually larger than the floor plan because it includes slope area (pitch), overhangs, and covers garages. A 2,000 sq ft home might have a 2,400 sq ft roof. For multi-story homes, the roof can be much smaller than total living space.
How accurate are satellite roof measurements?
Accuracy varies with imagery quality and age, subject-building selection, attached structures, trees, and roof complexity. Treat the result as a planning estimate and verify the building and dimensions on site before a claim, contract, final bid, or material order. They work well for most homes, though complex roofs, heavy tree cover, or very recent construction may affect accuracy. Learn more about satellite measurement accuracy.
What’s a roofing “square”?
A roofing square equals 100 square feet. Contractors and suppliers price materials by the square. So if your roof is 2,500 sq ft, that’s 25 roofing squares. Learn more about roofing squares.
Do I need to know my roof pitch to calculate area?
Yes, for manual calculations. A steeper pitch means more surface area than a flat roof over the same footprint. Our satellite tool automatically factors in pitch when calculating total area.
How do I convert roof pitch to a multiplier?
Divide the rise by 12, square it, add 1, and take the square root: multiplier = √(1 + (rise ÷ 12)²). A 6/12 pitch gives about 1.118, 8/12 about 1.202 and 12/12 about 1.414. Multiply the footprint by it: a 1,500 sq ft footprint at 6/12 is about 1,677 sq ft of roof surface. The calculator above does this for every pitch from flat to 12/12.
Related Tools & Guides
Use this result to plan your next step
Explore homeowner tools · Understand your report · Compare quote scope
Use available records and planning estimates as a starting point, then verify the details before work begins.