How to Measure a Roof with Google Maps

You can estimate a roof size using Google Maps without leaving your desk. While it is not as accurate as professional tools, it works well enough for rough estimates and initial quotes. Here is how to do it step by step, plus faster alternatives that give you more data.

Method 1: Google Maps Satellite View (Free)

This is the most basic approach. It is completely free but only gives you a rough footprint area without accounting for pitch.

Step 1: Open Google Maps at maps.google.com and search for the property address.

Step 2: Switch to Satellite view by clicking the Layers button in the bottom left corner and selecting Satellite.

Step 3: Zoom in until you can clearly see the roof outline.

Step 4: Right-click on one corner of the roof and select Measure Distance.

Step 5: Click along the edges of the roof to create an outline. Google Maps will show you the distance of each edge.

Step 6: Calculate the area by multiplying length times width for each rectangular section of the roof.

This gives you the roof footprint — the flat area as seen from above. For a rough estimate, this works. But for an accurate material quote, you need to account for roof pitch, which Google Maps does not measure.

Method 2: Google Earth Pro (Free)

Google Earth Pro is a free desktop application that offers more precise measurement tools than Google Maps. You can download it at google.com/earth.

Step 1: Download and install Google Earth Pro (it is free).

Step 2: Search for the property address.

Step 3: Use the Polygon tool to trace the roof outline.

Step 4: Google Earth Pro will calculate the area of the polygon in square feet or meters.

This is more accurate than Google Maps for the footprint, but you still need to apply a pitch multiplier manually. If you know the pitch is 6/12, multiply the footprint area by 1.118 to get the true roof surface area.

The Problem with Google Maps for Roofing

Google Maps and Google Earth give you the flat footprint of a roof, not the actual surface area. For roofing, this is a critical difference. A 2,000 sq ft footprint with a 6/12 pitch is actually 2,236 sq ft of roof surface. That is an extra 2.36 squares of material. With a steep 12/12 pitch, that same footprint becomes 2,828 sq ft — over 8 additional squares.

Other limitations of measuring with Google Maps include no pitch detection, no facet breakdown, no waste factor calculation, no material cost estimates, and the time it takes to manually trace each roof section. For a simple gable roof this takes 5-10 minutes. For a complex hip roof with dormers it can take 30 minutes or more.

Pitch Multipliers You Need

If you measure the footprint with Google Maps, apply these multipliers to get the actual roof area:

Method 3: Satellite Measurement Tools (Fastest)

Satellite roof measurement tools like ExactSquares use the same Google satellite imagery but combine it with AI and 3D roof modeling to automatically calculate the true roof area including pitch. Instead of spending 10-30 minutes tracing a roof in Google Maps, you enter an address and get results in 10 seconds.

What you get that Google Maps does not provide: total true surface area (not just footprint), number of roofing squares, predominant pitch detected automatically, number of roof facets, waste factor calculations at 10% and 15%, shingle cost estimates for GAF Owens Corning and CertainTeed, and a breakdown of each roof segment with individual area and pitch.

Google Maps vs Satellite Measurement Tools

Google Maps works for occasional rough estimates. But if you are measuring roofs regularly for quotes, the time savings alone justify using a dedicated tool. A contractor measuring 5 roofs per week saves 2-3 hours by switching from Google Maps to a satellite measurement tool.

Last updated: June 2026.