CTR calculator
Click-through rate from clicks and impressions, with cost per click.
Fill in the fields and the result will appear here automatically.
CTR relates recorded clicks to ad impressions. It helps compare response to an ad on a matched reporting basis, but it does not measure the share of buyers or replace cost per sale. An impression is an event, not necessarily a unique person. Optional spend adds CPC and CPM. Clicks above impressions retain the ratio with a warning so that the report can be checked.
How it works
Formula and logic
CTR = 100 × clicks K / impressions I percent. Impressions per click = I/K when K > 0. If spend C > 0, CPC = C/K for K > 0 and CPM = 1000C/I. Zero clicks give CTR 0 and no defined CPC. Input counts are not rounded. Ordinary CTR uses two decimal places; a positive CTR below 0.01% uses four, with still smaller nonzero values retained.
Example
1,250 clicks and 84,000 impressions give CTR 1.488095…%, displayed as 1.49%. Spend of 25,000 monetary units gives CPC 20.00 and CPM 297.62. Zero clicks on 5,000 impressions give CTR 0; one click on a million impressions gives 0.0001%.
Fields and units
- Clicks — unitless
- Impressions — unitless
- Campaign spend — $
How to use
- — Enter a nonnegative whole click count and a positive whole impression count for one period.
- — Match the campaign, placement and event-filtering rules of the two counts.
- — Spend is optional: blank or 0 omits the money rows; negative spend is rejected.
- — Review conversions and outcome quality alongside CTR rather than using a universal benchmark.
Method and limitations
- Calculation method
- Formula and logic
- Data or methodology source
- Google Ads: CTR defined as clicks relative to impressions
- Limitation
- A ratio of matched reporting events. Unique buyers, causal explanations, industry thresholds and profit are not estimated.
FAQ
Does the CTR impression count mean distinct people?
No. A person may receive repeated impressions. Replacing impressions with unique reach changes the denominator and the metric.
How should a CTR above a hundred percent be read?
The ratio is retained with a warning. Check dates, filters, repeated click events and platform definitions; do not automatically read it as the share of unique people who clicked.
Why can zero clicks give zero CTR but no CPC?
CTR divides zero by positive impressions. CPC would divide spend by zero clicks, so it has no defined value.
Does a higher CTR prove better sales performance?
No. It describes clicks relative to impressions. Visitor intent, conversions, prices and revenue need separate analysis; the formula does not establish the cause of a CTR change either.