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How to measure a roof from satellite imagery (footprint area)

Switch to Satellite, tap Measure > Measure Area, tap each corner of the roof edge. What you get is the footprint — the flat area seen from directly above — not the sloped surface. A plain rectangular roof comes out at 1,545.3 ft² with a 157.7 ft perimeter. No pitch setting anywhere in the app.

2 min read · Updated 2026-09-07

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What a satellite roof measurement gives you

From above, imagery shows the roof outline, overhangs included. Trace it and you get the footprint, the plan area. It's a fast first number — sizing a job, comparing two houses, sanity-checking a figure someone quoted you — before a ladder ever goes up.

Same outline's perimeter gives a first estimate for gutters and eaves, since those run along the roof edge anyway.

Steps in LandMeasure

  1. In Settings > Units, set Area to Square Feet (ft²) and Distance to Feet (ft).
  2. On the Map tab, choose Satellite from the map button and zoom in on the building.
  3. Tap Measure > Measure Area.
  4. Tap each outer corner of the roof edge in order, including every jog around dormers or wings.
  5. Read Area and Perimeter, adjust any handle that is off, and tap the green checkmark.

Worked example: a rectangular roof

Four corners traced on satellite imagery
FigureValue
Footprint area1,545.3 ft² (143.6 m²)
Perimeter157.7 ft (48.1 m)

Footprint versus roof surface

A pitched roof always has more surface than its footprint, since every slope is tilted away from flat. LandMeasure has no idea what your pitch is and makes no attempt to correct for it — that part is entirely on you, with a pen and a calculator.

Calculation outside the app, for a single 6/12 pitch
StepValue
Pitch factor for 6/12 = √(1 + (6/12)²)1.118
1,545.3 ft² footprint × 1.118about 1,727.7 ft² of roof surface

Several pitches, valleys, dormers — once a roof gets that complicated, each plane needs its own measurement. That's your roofer's job, on site, with their own tools, not an app looking straight down from orbit.

Tips for tracing roofs

  • Trace the outer edge, not the walls — imagery shows the overhang, and that's what you want.
  • Imagery can lean on tall buildings when shot at an angle. Trace the eave line, not the ridge's shadow.
  • A hidden corner under a tree? Guess it from where the two straight edges on either side would meet.
  • Switch to Hybrid when street labels are the only way you'll find the right house.

With LandMeasure Pro, that project turns into a PDF Report for a client: a map picture, the totals, a table per shape.

Questions and answers

Does LandMeasure calculate roofing squares?
No, just the footprint area. A roofing square is 100 ft², so once you've worked out the real surface, divide by 100 to get squares.
Can I enter the roof pitch?
No. Flat footprint only — pitch correction is a calculation you run outside the app, with your own numbers.
How do I calculate roof area from a map picture?
Trace the outline to get the footprint first, then apply a pitch factor to each roof plane separately — footprint alone will undersell the real area.

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