How tight to draw your circle: radius and catchment for clinic Google Ads

Here is the thing almost nobody tells you. Google's auction is run per search, and it is local. When someone in your suburb types physio near me, Google runs a fresh auction for that one query, in that one spot, at that one moment.

Your actual cost per click is whatever it takes to clear the Ad Rank threshold and just beat the competitor ranked directly below you. You usually pay less than your maximum bid. But the more rivals with strong Ad Rank standing in that local auction, the higher the price everyone pays to win.

So the kilometre count is not what drives your cost per booking. The number of clinics bidding inside that kilometre is. A click two streets from the beach and a click in a quiet outer suburb can cost wildly different amounts for the same search, because one auction is crowded and one is nearly empty.

Once you see it this way, the radius stops being a question about travel and becomes a question about competition. That single reframe changes how you draw the circle.

The instinct is to point your ads at the busiest, wealthiest, most populated patch you can reach. Every clinic owner feels the pull of it. That is exactly where the auction is most brutal.

Healthcare is consistently one of the most expensive verticals to advertise in, well above the average cost per thousand impressions across industries. Now layer a postcode where a dozen clinics are all bidding on the same terms, and you are paying a premium on top of a premium.

I was guilty of this thinking in my own clinic years ago. I assumed more people meant cheaper patients. The opposite is true when those people are surrounded by choice and surrounded by competitors all paying to be seen.

The winning move is the one that feels wrong. In a dense metro you go deliberately tight, and you hunt the pockets where fewer clinics are bidding, because that is where the auction is cheap and your money goes furthest.

Before you touch the radius, there is one setting that wastes more clinic budget than any other, and it is buried under Settings, then Locations, then Location options.

Google gives you two target options. Presence or interest reaches people who are in your area, regularly in your area, or who have merely shown interest in it by searching about it from somewhere else. Presence reaches only people who are in or regularly in your area. Presence or interest is the default and the setting Google recommends.

For a clinic, presence or interest is wrong. Your patient has to physically walk through your door. Someone in Perth googling a Bondi physio for their sister is not a patient, but presence or interest will happily show them your ad and charge you for the click.

Set it to Presence on every campaign. Check it more than once, because it resets to the default and hides where nobody looks. Interest based reach is built for research style intent, the way people look into travel, property or a course from anywhere, which has nothing to do with a bricks and mortar clinic patients have to attend in person.

Forget how far you wish patients would drive. Start by measuring how crowded your auction actually is, then size the circle to match.

Drop your clinic on Google Maps and count direct competitors, same modality, at three kilometres, five kilometres and eight kilometres. That count is your real input, not the population, not the suburb's income.

If you have eight or more competitors inside five kilometres, you are in a dense auction. Start tight, around five kilometres, and only expand into rings where your data later shows real bookings. If you have zero to two competitors inside eight kilometres, you can start wide, ten to fifteen kilometres, because the auction is cheap and patients will travel further when there is less choice nearby.

One guardrail. Google's minimum radius is one kilometre, but anything under about two to three kilometres can starve the campaign of impressions if the targetable population falls below Google's serving thresholds. If you need to go that tight, target the specific suburb or postcode rather than a tiny circle.

Here is where the contrarian move pays off. Where fewer clinics bid, the Ad Rank thresholds and competitor pressure are lower, so your actual cost per click and your cost per booking fall. Same patient, same intent, cheaper auction.

I have run a four kilometre radius on a clinic purely to keep it out of a neighbouring high competition suburb, Hawthorn, where the density would have lifted the price on every click. I have used a three kilometre radius in a dense pocket and a wide radius across underserviced regional areas, and the regional cost to acquire dropped well below what the metro postcode would ever allow.

The tactic is to build separate ad groups or campaigns for the quieter suburbs, with the suburb name in the headline, in the ad copy and on the landing page. Location based searches like physio near me and suburb names carry very high buyer intent and show in the map pack.

Mirroring the suburb end to end lifts your ad relevance and landing page experience, two of the inputs into Ad Rank, which lowers your cost per click in exactly the local auction you care about. The geography is not just a target setting, it is a relevance signal.

Gut feel sets your starting radius. Data sets your final one. The tool for this is Google's Distance report, which shows the distance between the location that triggered your ad and your closest clinic. You need location assets switched on for it to populate.

Read your conversions and cost per booking by distance band. If bookings hold out to six kilometres and then collapse, trim the radius to where the revenue actually is rather than paying for reach that never converts.

Distance affects more than conversion. In the accounts I run, clicks from the far edge of a wide circle tend to be worth less even when they convert, because the longer someone has to travel, the higher the no show risk. A booking is not the same as an attendance.

Pair the Distance report with the User Locations report in Report Editor, set to most specific location. That surfaces far suburbs eating spend with no bookings, and you add those as exclusions. Exclusions are presence only by default, so excluding a far suburb is clean and will not block someone genuinely in your area.

There is a classic tactic of layering concentric rings, an inner five kilometres, a middle ten, an outer fifteen, and bidding up the closest ring because near patients convert better and miss fewer appointments. It is a good tactic, but it only works on one type of bidding.

On manual or enhanced cost per click bidding, you can set location bid adjustments and the bid higher close, lower far plan actually runs. Build the rings as separate targets or campaigns and weight the closest one.

On Smart Bidding, target cost per acquisition or target return on ad spend, manual location bid adjustments are silently ignored. The classic ladder never executes, and plenty of owners set it up not realising it does nothing.

Under Smart Bidding you control geography a different way. Through your targeting boundaries and exclusions, and through Conversion Value Rules that tell Google a booking near the clinic is worth more. Smart Bidding still reads physical location and location intent as live signals, you just steer it with boundaries and value rather than bid modifiers.

Before you commit to a radius, it helps to see how competitor density bends your cost per booking. The estimator below is illustrative, not a quote, but it makes the mechanism concrete.

Put in the number of competing clinics inside your proposed radius, your monthly budget, and a base cost to acquire from a low competition area. Watch the expected cost per booking climb as the density rises, and watch how many patients that same budget buys you at each level.

The point is not the exact figure. The point is the slope. Adding bidders to your circle raises the price of every click in it, and a wider circle over a dense metro usually adds the most expensive bidders of all.

Use it to pressure test the wide radius you were about to draw, then compare it against a tighter circle over a quieter pocket.

If your account is already live, the fastest wins are sitting in three places. The Presence setting that may still be on the default. The Distance and User Locations reports you may never have opened. And the far suburbs you have never excluded.

Most clinics I look at are doing at least two of those three wrong, and each one quietly lifts the cost of every booking. None of them require a bigger budget. They require drawing the circle by competition, not by hope, and then letting the data tighten it.

Get the geography right and the same spend simply buys more patients. That is the whole game.