Vocabulary
Quality Score and CPC
By Oliver Wakefield-Smith, Digital Signet. Updated July 2026.
Quality Score is Google's 1-10 diagnostic for how useful your ad and landing page are for a keyword. It matters here because quality is an Ad Rank ingredient: better quality means you need less bid to hold a position, which shows up as a lower CPC.
Quality Score = expected CTR + ad relevance + landing page experience
The three documented components, each graded above average, average or below average against other advertisers. Google Ads Help, 2026 data
The mechanism, not a discount table
In the auction, your position depends on ad rank, and ad rank multiplies money by quality. The worked board on the auction page shows a 10-quality bidder holding first position on a £2.50 bid while a 5-quality bidder pays more for second. That is the whole relationship: quality substitutes for bid Google Ads Help, 2026 data.
You will find tables around the web promising exact CPC discounts per Quality Score point. Those are third-party estimates, not Google data, and most trace to models built over a decade ago. We do not reprint them. The direction is documented; the exact percentages are not.
Checking yours
In Google Ads: Keywords view, add the Quality Score columns (Quality Score, plus the three component columns). A 1-10 number appears once the keyword has enough impressions. Component grades tell you which lever is weak.
Improving it
Work the weak component. Below-average expected CTR: rewrite ads to match the query's intent more literally. Below-average ad relevance: tighten ad groups so each keyword sees an ad about itself. Below-average landing page experience: send the click to a page about the thing searched, not your homepage. Each is also a step on how to lower CPC; if your number is already high, diagnose first at why is my CPC so high or check the bid side at actual vs max CPC.