CPC is the amount you pay for each click on an ad; CPM is the cost of showing the ad a thousand times; CTR is the percentage of impressions that turn into clicks. The three are parts of the same equation: divide CPM by CTR and you get CPC. That is why "CPC went up" is not a diagnosis on its own; either impressions became more expensive or the ad is being clicked less, and the two have different fixes.
What Is CPC?
CPC stands for cost per click. You find it by dividing ad spend by the number of clicks. Spend 12,000 TRY, get 1,500 clicks, and your CPC is 8 TRY. The value you see in Google Ads and Meta reports is this average; not every click cost 8 TRY, some cost 3 and some cost 20.
In Google Ads the price of a click is set by auction: everyone who wants to advertise on the same search submits a maximum bid, and what you pay is just enough to beat the ad one position below you. If your ad's Quality Score is high, you get the same position for a lower click price. Meta works on similar logic; the difference lies in how crowded the audience is and how many advertisers compete for it.
What counts as a "normal" CPC varies by industry from a few TRY to a few hundred. In fields where a customer is worth a lot, such as law, insurance and software, clicks are expensive; in apparel and home goods they are cheap. Be careful using figures from outside your own account as a benchmark: even within the same industry, a brand search and a generic search can differ fivefold.
What Is CPM?
CPM stands for cost per mille: cost per thousand impressions. You calculate it by dividing spend by impressions and multiplying by a thousand. 12,000 TRY of spend for 400,000 impressions gives a CPM of 30 TRY. Where you buy impressions, on Meta, YouTube and the Display Network, this is the basic price indicator; in Google search ads, where you pay per click, CPM only appears as a derived report value.
A rising CPM is usually not about you. In November, before public holidays and during election periods, the number of advertisers wanting to reach the same audience rises and impressions get dearer. Knowing how CPM moves across the year lets you tell "our ads got worse" apart from "the market got more expensive" in November.
What Is CTR?
CTR is click-through rate: clicks divided by impressions. 1,500 clicks from 400,000 impressions is a CTR of 0.375%. It measures how appealing the ad was to the person who saw it; it is the combined result of copy, image, offer and targeting.
CTR has no good or bad value on its own; it gains meaning from what it is compared with. In Google search ads, above 20% on brand searches and 3% to 8% on generic searches are ordinary values; in the Meta feed around 1% is usual and above 2% is considered good. These ranges are not fixed thresholds but starting points for comparing your own account against its history.
How the Three Relate
These three metrics are not independent of each other. You buy impressions with money and earn clicks through CTR; the cost of a click is therefore the result of those two:
This equation tells you where to look when you spot a deviation in a report. CPC up and CTR unchanged: impressions got dearer, competition or seasonal effect. CPC up and CTR down: the ad has worn out or the audience was widened; look at creative and targeting. CPC down and CTR up: looks like good news, but if conversion rate also fell you are collecting cheap, irrelevant traffic.
| Observation | Likely cause | First place to look |
|---|---|---|
| CPC ↑, CTR flat | Impressions got more expensive | CPM trend over time, competition |
| CPC ↑, CTR ↓ | Ad is losing interest | Creative age, audience expansion, frequency |
| CPC ↓, CTR ↑, conversions ↓ | Irrelevant traffic | Search terms, placements, audience |
| CPM ↑, CTR ↑ | Narrower but pricier audience | Did cost per conversion change |
Two Ways to Lower CPC
Cutting the bid is the first idea that comes to mind for lowering click cost; most of the time the result is fewer impressions and the same CPC. A lasting drop comes from two places. In Google Ads, Quality Score: the relevance of your ad copy to the search, the expected click-through rate and the landing page experience are scored from 1 to 10; a keyword that moves from 7 to 9 gets the same position noticeably cheaper. On Meta, frequency: an ad shown to the same person five times a week sees its click-through rate fall, CPM stays the same and CPC rises. Refreshing the audience or changing the creative does more than cutting the bid.
The second way is not to narrow targeting but to cut off the wrong traffic. Adding queries with no connection to a sale as negative keywords in the search terms report raises both CTR and conversion rate; CPC falls because the clicks you now pay for come from relevant people.
CPA: The Question Beyond These Three
CPC, CPM and CTR answer "at what price, to how many people, with how much interest"; they do not answer "how much did I sell". For that you look at CPA, cost per acquisition: spend divided by the number of conversions. 12,000 TRY of spend and 60 sales means a CPA of 200 TRY. For an e-commerce store this is the real decision metric; whether CPC is 8 or 12 matters less than whether the cost per sale stays below the product margin.
The same logic on the revenue side uses ROAS; we covered it in detail in what is ROAS and what counts as a good ROAS. The short way to read the metrics in one table: CPM and CTR describe the ad's entry, CPC its cost, CPA and ROAS its outcome.
Which Metric to Look at When
CTR and CPC. A sudden drop or rise shows a creative or budget problem here first. Compare daily fluctuation against the weekly average.
CPA and ROAS. Which campaign gets more budget and which gets cut is answered here. Budget is not increased just because clicks are cheap.
The CPM trend. Talking about campaign success without separating seasonal and competitive effects is misleading.
One more small warning: metrics that appear under the same name in Google Ads and Meta reports are not calculated the same way. Meta separates "clicks (all)" from "link clicks"; the first also counts likes and comments. In Google, "engagements" and "clicks" are different columns. When putting the two platforms side by side, use link clicks as the base, otherwise Meta's CTR looks better than it is.
In AdsLuma, the ad screens calculate CPC, CPM, CTR and CPA for Google Ads, Meta and LinkedIn with the same definitions and place them side by side; when you ask Luma AI "why did CPC rise this month", it makes the distinction above with your own data.
Frequently Asked Questions About Ad Metrics
What does CPC mean and how is it calculated?
It means cost per click. Total ad spend is divided by the number of clicks: for 12,000 TRY of spend and 1,500 clicks, CPC is 8 TRY.
What is the difference between CPM and CPC?
CPM is the cost of an impression, CPC the cost of a click. On platforms where you buy impressions, CPM is the base price; in search ads, where you buy clicks, it is CPC. CTR links the two: CPC is CPM divided by CTR.
What is a good CTR?
It depends on the platform and the type of search. In Google search ads, 3% to 8% on generic searches and above 20% on brand searches; in the Meta feed, around 1% is an ordinary value. Comparison with your own history is more meaningful than an industry average.
Why can sales be low when CTR is high?
The ad is creating an expectation the page does not meet; or the ad is being shown to an audience that is interested but not ready to buy. Conversion rate and CPA need to be read together with click-through rate.
AdsLuma calculates Google Ads, Meta and LinkedIn data with the same formulas in one panel; Luma AI explains why a metric moved.
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