The email click-through rate formula is unique clicks divided by delivered emails, multiplied by 100. If 8,400 messages were delivered and 273 unique recipients clicked, your CTR is 273 ÷ 8,400 × 100 = 3.25%. The two details that trip people up are using delivered rather than sent, and counting unique clickers rather than total clicks.
The formula, and the denominator decision
Written out:
CTR = (Unique clicks ÷ Emails delivered) × 100
Delivered means sent minus bounces. Using sent instead of delivered inflates your denominator with messages nobody could possibly have clicked, which understates performance — and does it inconsistently, because your bounce rate changes from send to send. If you have ever seen CTR drop after a list import, this is often why.
The gap is not academic. On a send of 10,000 with a 4% bounce rate, the two denominators differ by 400 messages, which is enough to move a reported CTR by a couple of tenths of a point. Pick delivered, use it everywhere, and note which one your platform reports by default so your historical comparisons stay honest.
A worked example
| Input | Value |
|---|---|
| Emails sent | 9,000 |
| Bounces | 600 |
| Emails delivered | 8,400 |
| Unique opens | 2,100 |
| Unique clickers | 273 |
| Total clicks (including repeats) | 412 |
From those numbers:
- CTR = 273 ÷ 8,400 × 100 = 3.25%
- Total-click rate = 412 ÷ 8,400 × 100 = 4.90%
- Open rate = 2,100 ÷ 8,400 × 100 = 25.0%
- Click-to-open rate (CTOR) = 273 ÷ 2,100 × 100 = 13.0%
Note how the same campaign produces 3.25% or 4.90% depending purely on whether you count unique clickers or every click. Neither is wrong, but mixing them across reports is. Use unique clicks as your headline number and keep total clicks as a secondary signal — a large gap between them usually means one link is being re-clicked, which tells you where the interest is.
CTR, CTOR, and conversion rate are three different questions
| Metric | Formula | Question it answers | Mostly influenced by |
|---|---|---|---|
| Click-through rate | Unique clicks ÷ delivered | How much action did this send produce overall? | Subject line, list quality, offer |
| Click-to-open rate | Unique clicks ÷ unique opens | How persuasive was the message once opened? | Body copy, CTA, layout |
| Conversion rate | Conversions ÷ delivered | Did the click turn into value? | Landing page, offer, friction |
| Click-to-conversion | Conversions ÷ unique clicks | Did the destination keep the promise? | Landing page match |
The practical rule: use CTR to compare campaigns of the same type over time, use CTOR to judge creative and copy decisions, and use conversion rate to decide whether the campaign was actually worth sending.
A common trap is celebrating a CTR increase that came entirely from a better subject line. More people opened, so more people clicked, but the email itself was no more persuasive. CTOR would have stayed flat and told you the truth.
Why your CTR is probably slightly wrong
Every reported click number contains some noise. Knowing the sources keeps you from over-reacting to small movements.
- Security scanners. Corporate mail gateways follow links in messages to check for malware, generating clicks no human made. B2B lists are affected far more than consumer lists, and the effect is concentrated in the first minutes after delivery.
- Privacy proxies. Image and link proxying inflates opens heavily and, to a lesser degree, distorts click attribution and geography.
- Link tracking failures. If a link was not wrapped for tracking, its clicks are invisible. Check that plain-text versions and any hand-edited HTML use tracked URLs.
- Multi-device readers. The same person clicking on a phone and a laptop may register as one clicker or two depending on how your platform de-duplicates.
- Unsubscribe and preference clicks. Some platforms include footer links in the click count. That is not engagement, and it can meaningfully lift CTR on a campaign that annoyed people.
Two defenses. First, filter clicks that arrive within a couple of seconds of delivery, which are almost certainly automated. Second, judge campaigns against your own trailing average rather than an absolute target — noise that is consistent across sends cancels out in a trend line.
What counts as a good click-through rate
Published benchmarks vary enormously by industry, list source, and how each platform defines its terms, so treat any single figure with suspicion. As broad orientation, email click-through rates commonly land somewhere in the 2 to 5 percent range, with click-to-open rates typically running considerably higher — often in the low-to-mid teens.
Those ranges are less useful than three internal comparisons:
- Your own trailing six-send average for the same campaign type. Newsletters and promotions are not comparable to each other.
- Segment against segment. If your 30-day actives click at 9% and your 12-month segment clicks at 0.4%, the problem is list composition, not copy.
- Variant against variant. An A/B test on the same list at the same moment removes almost every confounding factor.
Practical ways to move the number
- Cut the number of distinct destinations. Four competing links usually produce fewer total clicks than one, because choice creates deferral.
- Move the primary link higher. Many readers never scroll past the first screen on a phone.
- Rewrite button copy to name the outcome. "See the September rates" outperforms "Learn more" consistently.
- Segment by engagement before you rewrite anything. Removing 12-month dormant subscribers from a send often lifts CTR more than any copy change, because the denominator was full of people who were never going to click.
- Link the images too. Readers click images expecting them to work. An unlinked hero image is a wasted click.
- Match the destination headline to the button text. It does not change CTR but it protects the conversion rate that CTR is supposed to be feeding.
From clicks to money
CTR is a diagnostic, not a goal. You can raise it by mailing only your 500 most engaged subscribers and never touching anyone else — and watch revenue fall. Always pair it with an absolute number.
Track clicks alongside revenue per send and revenue per subscriber so a rate improvement has to survive contact with the total. If you want to work out what a change in click and conversion rates is actually worth on your list size and margins, run the numbers through our email marketing ROI calculator before you commit to a testing plan.
One more habit worth building: record CTR, CTOR, and conversion rate for every send in a single sheet alongside the send date, segment, and subject line. Six months of that is worth more than any industry benchmark report, because it is measured on your list, by your platform, using your definitions.
Frequently asked questions
What is the formula for email click-through rate?
Divide unique clicks by emails delivered, then multiply by 100. Use delivered rather than sent, since bounced messages could never have been clicked and including them distorts comparisons between sends.
Is click-through rate the same as click-to-open rate?
No. Click-through rate divides clicks by delivered emails and reflects the whole send, while click-to-open rate divides clicks by unique opens and isolates how persuasive the message was for people who actually read it.
Should I use unique clicks or total clicks?
Use unique clicks for your headline CTR so one enthusiastic reader cannot skew the result. Keep total clicks as a secondary signal, since a large gap between the two shows which links people return to.
What is a good email click-through rate?
Most senders land somewhere in the 2 to 5 percent range, but industry, list source and platform definitions vary so widely that the number is only loosely useful. Compare each send to your own trailing average for the same campaign type instead.
Why did my click-through rate suddenly drop?
The most common causes are a list import that expanded the denominator with unengaged contacts, a broken or untracked link, or a send to a wider segment than usual. Check link tracking and segment composition before assuming the copy was the problem.
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