Advertising

Google Ads metrics: what CTR, conversion rate and Quality Score tell you

Understand the numbers in your Google Ads report, what sits behind each percentage and how to use them to make practical advertising decisions.

By Onside Growth

7 October 20265 min read

Your Google Ads report contains numbers that answer different questions. CTR helps explain whether an ad attracts clicks. Conversion rate helps explain what happens after an interaction. Quality Score can point to an experience worth investigating.

Reading them together is more useful than treating one green arrow as proof of success. For an Australian business owner, the goal is to understand where performance changed and what to check next.

Start with the counts behind the rates

An impression records an ad being shown; it is not a count of unique people. Clicks record clicks on the ad. CTR connects these counts: clicks divided by impressions, multiplied by 100. Keep both counts visible beside the percentage so you can see the activity behind it.

Reference: Google Ads Help — Clickthrough rate (CTR): Definition

CTR: does the ad attract a response?

CTR means clickthrough rate. Google describes it as a way to assess how well ads and keywords perform. A useful comparison depends on what you advertise and the network where the ad appears. There is no single good CTR for every campaign.

A change can prompt a review of the message, offer and audience. Before rewriting an ad, check whether the mix of searches or placements changed. A campaign showing for your own business name answers a different question from one reaching people who have never heard of you. Compare like with like, then ask whether the extra clicks were useful.

Reference: Google Ads Help — Clickthrough rate (CTR): Definition

Conversion rate: which interactions produce the recorded action?

Google Ads calculates conversion rate as conversions divided by ad interactions that can be tracked to a conversion in the same period, multiplied by 100. The denominator is not impressions or website sessions. In a straightforward Search example, those interactions may be clicks.

The numerator also matters. Ask which conversion actions appear in the report: purchases, enquiries, bookings or supporting actions. A percentage based on several actions is different from one based only on purchases. Google notes that conversion rate can exceed 100% when more than one conversion is counted per interaction.

Reference: Google Ads Help — Conversion rate: Definition

Counting settings can change the result

For each conversion action, Google Ads offers 'One' and 'Every' counting options. 'One' counts one conversion for that action per ad click; 'Every' counts each conversion for the tracked action after an interaction. The appropriate choice depends on what adds value: one lead from a click may be useful, while several separate purchases can each matter.

Check these settings before comparing reports. An increase following a counting change needs a different explanation from an increase in customer activity. State what changed so next month's comparison remains understandable.

Reference: Google Ads Help — About conversion counting options

Quality Score: a diagnostic for Search ads

Quality Score is a keyword-level diagnostic on a scale of 1 to 10. Google explicitly says it is not a key performance indicator and is not an input in the ad auction. Avoid turning an average score into the main measure of campaign success.

Its three components are expected CTR, ad relevance and landing-page experience. Expected CTR assesses the likelihood of a click. Ad relevance assesses the match to the search intent. Landing-page experience assesses how useful and relevant the destination is. These receive 'Above average', 'Average' or 'Below average' statuses based on comparisons with other advertisers showing for the same searches over the previous 90 days.

A component status gives you a place to investigate. It does not establish that a campaign is profitable, and an improved score does not guarantee cheaper clicks or more customers.

Reference: Google Ads Help — About Quality Score for Search campaigns

Use the components to choose a review

Google recommends reviewing the components rather than focusing only on the overall score. For weaker expected CTR, examine whether the offer and call to action are clear. For weaker ad relevance, review how closely the message fits the targeted intent. For weaker landing-page experience, check whether the destination delivers the advertised offer and is usable on a phone.

Choose a specific issue to test, record the change and review actual campaign outcomes alongside the diagnostic. Avoid changing several unrelated things at once if you want to understand which adjustment helped.

Reference: Google Ads Help — 5 ways to use Quality Score to improve your performance

An example of why one percentage is not enough

Illustrative example only: campaign A receives 8,000 impressions, 400 clicks and 20 enquiry conversions. Its CTR is 5%. Assume all 400 clicks are eligible interactions for the calculation: its conversion rate is also 5%.

Campaign B receives 8,000 impressions, 600 clicks and 18 enquiry conversions. With the same assumption, its CTR is 7.5% and conversion rate is 3%. It attracted more clicks but produced fewer recorded enquiries. These are invented teaching figures, not benchmarks. To choose between campaigns, you would also need the cost and quality of those enquiries.

Ask for an explanation you can act on

Keep the date range, conversion definitions and campaign context consistent when reviewing performance. Small counts can make percentage changes look dramatic. Ask what changed, what evidence supports the explanation and what the proposed test should show.

Onside Growth can help turn your Google Ads report into clear questions and practical next steps. Use the metrics to diagnose the campaign, then judge the decisions by useful business results.