Using Google Maps to Measure Area — How to Estimate Square Footage for Pressure Washing Bids

By Jason Geiman, King of Pressure Wash | 126,000+ views on YouTube

One of the biggest challenges when you're first starting a pressure washing business is figuring out how to bid jobs accurately — especially when you're quoting over the phone or by email and haven't seen the property yet. Google Maps is a free tool that can give you a surprisingly accurate measurement of driveways, roofs, patios, and other surfaces so you can estimate square footage and build your bids without driving to every property first.

I've been using Google Maps to measure properties for over 15 years, and it's saved me countless hours of driving to estimate jobs. In this post, I'll show you how to use Google Maps to measure area for pressure washing bids, when it's accurate enough to rely on, and when you still need to do an in-person visit.

How to Measure Area Using Google Maps

Step 1: Open Google Maps and find the property

Go to Google Maps on your computer and type in the property address. Once the map loads, switch to satellite view so you can see the actual property layout — the driveway, roof, patio, sidewalks, and other surfaces you'll be cleaning.

Step 2: Use the Measure Distance tool

Right-click on the map and select "Measure distance." This lets you click points on the map to create a path and measure distances between them. You can use this to measure the length and width of a driveway, patio, or any rectangular area. Multiply the length by the width to get the square footage.

Step 3: Outline irregular shapes

Not all surfaces are perfect rectangles. For L-shaped driveways, curved walkways, or irregular patios, you can click multiple points along the perimeter to outline the shape. Google Maps will show you the total area enclosed by your points. This is especially useful for oddly shaped driveways and large commercial properties.

Step 4: Measure the roof

For roof cleaning estimates, you can outline the footprint of the roof from the satellite view. Keep in mind that the satellite view shows the roof from above, so the measurement you get is the horizontal footprint — not the actual roof area. Pitched roofs have more surface area than their footprint suggests. A general rule of thumb is to add 15-30% to the footprint measurement depending on the roof pitch to account for the slope.

What You Can Measure with Google Maps

Driveways — These are the most common surface you'll measure for pressure washing bids. Driveways show up clearly on satellite view, and you can usually get a very accurate measurement of the length and width.

Roofs — You can see the roof outline clearly from satellite view. Remember to account for the pitch when calculating actual roof area.

Patios and pool decks — These are usually visible from satellite view, though they may be partially obscured by trees or covered structures.

Sidewalks and walkways — Measure the length from Google Maps and use a standard width (most residential sidewalks are 3-4 feet wide).

Commercial parking lots and building facades — For large commercial properties, Google Maps is invaluable. Measuring a 50,000 square foot parking lot in person with a measuring wheel takes a long time. Google Maps gives you a very close estimate in minutes.

When Google Maps Isn't Enough

Heavily wooded properties. If the property is surrounded by trees, the satellite view may not show the surfaces you need to measure. Tree canopy can completely hide driveways, patios, and walkways. In this case, you'll need to visit the property in person or ask the homeowner for photos.

Properties with recent changes. Google Maps satellite imagery is not updated in real time. The images can be months or even years old. If the homeowner has recently added a patio, extended a driveway, or built a new structure, the satellite view won't show it. Always ask the customer if anything has changed since the satellite image was taken.

Complex commercial properties. While Google Maps is great for getting a general estimate of a commercial property, very complex jobs with multiple levels, vertical surfaces, and difficult access still benefit from an in-person site visit. Google Maps can't tell you about the condition of the surface, the severity of the staining, or access challenges.

When precision matters for the bid. Google Maps measurements are estimates — they're usually within 5-10% of the actual measurement. For standard residential work, that's close enough. For large commercial jobs where a 10% error could mean thousands of dollars, consider verifying your Google Maps estimate with an in-person measurement.

Tips for More Accurate Measurements

Zoom in as far as possible. The more zoomed in you are, the more precisely you can place your measurement points on the edges of the surface. Zoomed-out measurements are less accurate because small cursor movements represent larger distances.

Use known reference points. If you know the width of a standard two-car garage (about 16-18 feet), you can use that as a reference to verify your measurements are in the right ballpark.

Break complex shapes into rectangles. Instead of trying to outline an L-shaped driveway in one measurement, break it into two rectangles, measure each one separately, and add them together. This is often more accurate than trying to click dozens of points along an irregular shape.

Account for slopes and elevation changes. Google Maps measures horizontal distance — it doesn't account for slopes. A steeply sloped driveway will have more surface area than what Google Maps shows. Factor in a small buffer for sloped surfaces.

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