Use this CTR calculator to measure click-through rate from clicks and impressions. Enter valid clicks and total impressions for the same campaign, ad, search result, or email period. The calculator returns CTR as a percentage and decimal ratio so you can compare performance across channels and spot reporting issues quickly.
What is CTR?
Click-through rate (CTR) measures how often people click compared to how often they see something (impressions). It’s used across ads, search results, and emails.
Formula
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- Reference: [Click-through rate definition](./).
How to Use the CTR (Click-through Rate) Calculator
Follow these steps to calculate click-through rate from your ad metrics and see both percent and decimal CTR.
Enter impressions.
Type the total valid impressions for the period you are analyzing. Use impressions, not reach, and keep the period aligned with your clicks.
Enter clicks.
Input valid clicks from the same campaign, placement, email, or search result. Clicks must be non-negative and cannot exceed impressions.
Review percent and decimal CTR.
The calculator updates instantly with CTR percentage and decimal CTR. Use the percentage for reporting and the decimal ratio for models or exports.
Interpret the result.
Compare CTR against channel, placement, audience, and creative benchmarks. A low CTR can signal weak targeting, offer, creative, or search intent fit.
Frequently Asked Questions
These FAQs explain CTR inputs, valid clicks, valid impressions, decimal versus percent CTR, and common reporting differences.
What is Click-Through Rate (CTR)?
CTR is the ratio of valid clicks to valid impressions. In percentage form:
. In decimal form:
.
How do I compute CTR for 22 clicks and 3,859 impressions?
Compute
. As a percent,
. With standard rounding, report 0.57% (decimal 0.0057).
What inputs are valid for CTR?
Impressions must be greater than 0. Clicks and impressions must be non-negative integers with 0 <= clicks <= impressions, or in symbol form 0 <= C <= I. If impressions are 0, CTR is not defined.
Why might two systems show slightly different CTRs?
Differences typically come from (1) which clicks/impressions are considered “valid” after filtration (e.g., bot/fraud filtering), and/or (2) rounding/display rules (number of decimals, tie-handling). The mathematical ratio is the same when inputs and rounding rules match.
Should I use percent or decimal CTR?
Use either consistently. Percent is common for reporting (e.g., 0.57%), while decimal form (e.g., 0.0057) is convenient for modeling and calculations.
We compute CTR as the dimensionless ratio of valid clicks to valid impressions, then multiply by 100 for percent view:
with constraint
. Inputs are integers with 0 <= C <= I. Counts should reflect IAB/MRC filtering and audit practices before calculation. Arithmetic uses IEEE-754 round-to-nearest, ties-to-even for display; we show percentages to two decimal places and decimal CTR to four significant digits unless otherwise specified.
Sources & Methodology