How to use it
Tap CTR, Clicks or Impressions in the equation to choose what to find, then fill in the other two. CTR is entered and shown as a percentage: type 1.5 for 1.5%. You can add the % sign if you like; it makes no difference.
The same maths works anywhere something is shown and then clicked: search ads, display banners, a result in Google Search Console, a link in an email. Only the labels change.
The formula
Google Ads defines CTR as the number of clicks an ad receives divided by the number of times it is shown. As a percentage:
CTR = clicks ÷ impressions × 100
Clicks = impressions × CTR ÷ 100
Impressions = clicks ÷ CTR × 100
Worked examples
Finding CTR. 340 clicks from 21,500 impressions: 340 ÷ 21,500 = 0.015814, times 100 is 1.58%.
Clicks to expect. You plan 40,000 impressions and expect a 2.1% CTR. 40,000 × 2.1 ÷ 100 = 840 clicks.
Impressions you need. You want 500 clicks and your ads average a 1.25% CTR. 500 ÷ 1.25 × 100 = 40,000 impressions. Divide that by 1,000 and multiply by your CPM to price it, or use the CPM calculator.
| Clicks | Impressions | CTR |
|---|---|---|
| 340 | 21,500 | 1.58% |
| 840 | 40,000 | 2.10% |
| 500 | 40,000 | 1.25% |
CTR in email and search
Email. An email click-through rate is often worked out as clicks divided by emails delivered. A click-to-open rate divides clicks by opens instead, so it comes out higher. Both use the formula above; the difference is which number sits underneath. Say which one you are reporting.
Search Console. Google Search Console reports CTR for organic results as clicks divided by impressions, the same sum. Its help pages say an impression is generally counted when your link is on the current page of results, whether or not it was scrolled into view, with exceptions for carousels and infinite-scroll results.
Unique or total. Some tools divide unique clickers by unique people reached, others divide total clicks by total impressions. The two can differ a lot for an ad shown many times to the same people.
Why a CTR can mislead
A high CTR with few conversions can mean the ad promises something the landing page does not deliver. A low CTR on a cheap CPM can still produce cheap clicks. CTR also falls as you show an ad to colder audiences or show it more often. Read it next to CPC and conversion rate, not alone.
How this calculator handles your numbers
Your inputs are worked as exact fractions, so no rounding happens until the answer is shown. Percentages are rounded to two decimals, half away from zero. Clicks and impressions must be whole numbers, and answers that come out fractional are rounded to the nearest whole number with the exact value shown. More clicks than impressions, a CTR above 100% or zero impressions get a message rather than a result.