How to measure a roof for shingles: tape, satellite, drone and AI compared

To measure a roof for shingles, find the flat area of every roof plane, multiply it by the pitch multiplier and divide by 100 to get squares. Add 10% to 15% for waste, convert squares to bundles, then order starter and ridge cap by the linear foot.

The math is the same however you get the measurements: tape, satellite report, drone or AI. What changes is cost, speed and how often your crew climbs a ladder. Below we compare all four, then work one hip roof from footprint to final order.

What are the ways to measure a roof for shingles?

There are four: tape on the roof, a satellite report, a drone and AI from aerial imagery. Only the tape puts someone on the roof, and only the tape and the drone need a trip to the house.

Tape measure on the roof

You climb, measure every plane, check pitch with a gauge and sketch the roof. There is no report fee, but every roof costs a drive, ladder time and fall protection, and the numbers are only as good as the person holding the tape.

Satellite measurement reports

You order a report by address, and a provider measures the roof from aerial images. Nobody climbs, but you pay a fee on every report and wait for it to come back before you can price the job.

Drone measurement

A drone keeps your rep off the roof but not off the property. Flying for business requires an FAA Remote Pilot Certificate under Part 107, which means passing a knowledge test, plus a $5 drone registration that lasts 3 years.

AI from aerial imagery

AI measures the roof from aerial imagery while you sit at your desk or in the driveway. Artemis uses aerial imagery and LiDAR to deliver roof measurements in about 7 seconds.

When you need the full document, an Artemis roof report costs $5.75 to $12, ESX file included.

Comparison table of four roof measurement methods. Tape on the roof needs a site visit and a climb. Satellite reports need no visit or climb but carry a fee per report and a wait. Drones need a site visit and an FAA Part 107 certified pilot. AI from aerial imagery needs no visit or climb and returns roof measurements in about 7 seconds.

How dangerous is measuring a roof by hand?

Roofing is one of the deadliest jobs in the country, and falls drive the risk. The Bureau of Labor Statistics recorded 104 roofer deaths in 2024, a rate of 48.7 per 100,000 full-time equivalent workers versus 3.3 for all workers. That is 48.7 ÷ 3.3 = about 15 times the national rate.

OSHA reports 389 fatal falls to a lower level out of 1,034 construction deaths in 2024. Its residential fall protection guidance requires protection for work 6 feet or more above a lower level.

Those numbers cover all roofing work, not just measuring. But the sales-stage climb is one exposure you can remove completely.

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What is the roof pitch multiplier?

The roof pitch multiplier, or roof pitch factor, converts flat plan area into the sloped area you actually shingle. The formula is multiplier = √(rise² + 12²) ÷ 12, where rise is inches of climb per 12 inches of run.

For a 6/12 roof: √(36 + 144) ÷ 12 = 13.416 ÷ 12 = 1.118, so 100 sq ft of plan area becomes 111.8 sq ft of roof. Hips and valleys use a second factor on the run: √(rise² + 288) ÷ 12, exactly 1.5 at 6/12.

Table of roof pitch multipliers and hip and valley factors from 3/12 to 12/12, including 4/12 at 1.054, 6/12 at 1.118, 8/12 at 1.202 and 12/12 at 1.414

How many bundles of shingles are in a square?

Most 3-tab and architectural shingles come three bundles to a square, and a square is 100 sq ft of roof, according to GAF. Exceptions exist: GAF Woodland runs four bundles per square, and some specialty shingles need five.

Read the coverage on the wrapper, not just the count. Owens Corning Duration shingles are three bundles per square, but that square covers 98.4 sq ft, not 100. Divide total area by coverage per bundle and you catch the bundle that "squares × 3" misses.

How much should you add for waste, starter and ridge cap?

GAF tells contractors to add 10% to 15% for trim and waste on top of measured area. Steep slopes, valleys and dormers push you toward the high end.

Starter and ridge cap go by the linear foot. Starter runs along eaves and rakes, and Owens Corning Starter Strip Plus covers about 105 linear feet per bundle. Ridge cap covers ridges and hips, and Owens Corning ProEdge covers 33 linear feet per bundle.

How do you calculate shingles for a roof? A worked example

Multiply plan area by the pitch multiplier, add waste, then divide by coverage per bundle. Here is a 6/12 hip roof with a 52 by 32 ft plan (a 50 by 30 ft house plus 1 ft overhangs), using Owens Corning materials.

Plan area: 52 × 32 = 1,664 sq ft.
Sloped area: 1,664 × 1.118 = 1,860 sq ft. With rafters of 16 × 1.118 = 17.9 ft, that is two trapezoids of (52 + 20) ÷ 2 × 17.9 = 644 sq ft and two triangles of 32 ÷ 2 × 17.9 = 286 sq ft.
Squares: 1,860 ÷ 100 = 18.6.
Waste at 15%, the top of GAF's range, since hips mean cut shingles: 1,860 × 1.15 = 2,139 sq ft, or 21.4 squares.
Field bundles: 2,139 ÷ 32.8 = 65.2, so 66 bundles of Duration. The "21.4 squares × 3" shortcut gives 64.2, or 65, one bundle short.
Starter: eaves run 2 × (52 + 32) = 168 linear ft (a hip roof has no rakes). 168 ÷ 105 = 1.6, so 2 bundles.
Ridge cap: the ridge is 52 minus 32 = 20 ft, and each hip is 16 × 1.5 = 24 ft. 20 + 4 × 24 = 116 linear ft, and 116 ÷ 33 = 3.5, so 4 bundles.

Plan view diagram of a 52 by 32 ft hip roof at 6/12 pitch with a 20 ft ridge, four 24 ft hips, two 644 sq ft trapezoid planes and two 286 sq ft triangle planes, totaling 1,860 sq ft, 18.6 squares and an order of 66 shingle bundles, 2 starter bundles and 4 ridge cap bundles

Can AI measure a roof for shingles?

Yes. AI reads aerial imagery and returns the inputs this math needs, from plane areas to pitch and edges, with nobody on a ladder. Artemis Roofing then carries those measurements to the signed contract in one platform.

With the Shingle Visualizer, homeowners see new shingles on their own roof in real time. Solar reps can add a reroof to the same proposal with instant roofing quotes.

FAQ

How many squares is a 2,000 sq ft house?

It depends on the footprint, not the living space. A single-story 2,000 sq ft footprint at 6/12 has 2,000 × 1.118 = 2,236 sq ft of roof, or 22.4 squares, before overhangs and waste. A two-story house of the same size has about half that.

How do you find roof pitch without getting on the roof?

In the attic, hold a level against the underside of a rafter, mark 12 inches along the level and measure straight up to the rafter. That rise over 12 is your pitch. AI measurement gives you pitch for every plane without the attic trip.

Do you need a license to measure roofs with a drone?

For business use, yes. The FAA requires a Part 107 Remote Pilot Certificate, earned by passing a knowledge test, and a $5 drone registration that lasts 3 years.

Book a free demo to get roof measurements on your next address in about 7 seconds, with no ladder.