Google Ads radius for a local plumber: 10 miles or tight zip codes?

I keep going back and forth on how wide to draw the radius for a single-location plumber. Say the shop sits in a town of 200k with a few suburbs around it. A 10 mile radius covers everything and the CPCs look fine, but a good chunk of clicks come from the far edge, where the drive is 40 minutes and the crew would never take the job. Tight zip code targeting cuts that waste, but it also shrinks volume a lot, and emergency calls don't wait for a zip list to be updated.

My take is to start with a drive-time radius around the shop, then use call duration and booked-job data to trim the outer ring. Do others set the radius once and leave it, or review it monthly?

Google's radius is straight-line distance, not drive time, so a 10 mile circle can pull in a suburb across a river that's 40 minutes by car and miss one that's only 12 minutes away. Are your booked-job addresses clean enough to map drive time against?

Fair point on straight-line distance, and it changes how I'd handle the far ring. I'd keep the radius wide enough to catch emergency calls, then use a location bid adjustment to push the outer band down. Those clicks get cheaper but can still come in.

Also look at the presence versus interest setting in location targeting. Interest-based targeting shows your ads to people searching about your town from well outside it, and that's a separate source of far-away clicks. Are you running Search or Performance Max?

Check the interest setting first, because most people never look at it and it quietly feeds far-away clicks. Switch location targeting to "presence" only, then pull the location report and see where the clicks really come from.

For the radius, stop guessing and use your own booked jobs. Map the last year of job addresses, find where about 90% of them fall, and set the radius to cover that. Then exclude the outer areas that get clicks but no jobs. Bid adjustments on the far rings only help once you have enough conversions to tell the rings apart, and for a single plumber that can take months.

Presence only is the right call, and 90% is a solid place to start. One thing the booked jobs miss, though: they only show trips your crew already said yes to. A suburb 35 minutes out could be sending a lot of calls that got turned down for distance, and those never show up in your job list. Before you cut that ring, look through your call log for anything declined or lost because of the drive, assuming your team tags those. That tells you how much far-end demand you're turning away, and that's what decides whether the outer ring is wasted spend or just isn't worth serving.