Definition
Click-to-open rate (CTOR) measures the percentage of email opens that resulted in a click. Unlike open rate and click-through rate, CTOR isolates content performance from subject line effectiveness and deliverability.
CTOR answers the question: once someone opens your email, does your content convince them to take action? It is one of the purest measures of content quality and relevance.
Formula
CTOR uses unique clicks and unique opens to avoid double-counting.
CTOR = (Unique Clicks / Unique Opens) × 100
| Variable | Description |
|---|---|
| Unique Clicks | Number of individual recipients who clicked at least one link |
| Unique Opens | Number of individual recipients who opened the email at least once |
Average Benchmark
CTOR benchmarks are generally consistent across industries because the metric filters out deliverability and subject line differences.
| Industry | Average CTOR |
|---|---|
| Agriculture | 15.2% |
| Ecommerce | 16.8% |
| Education | 18.5% |
| Finance | 13.9% |
| Healthcare | 14.6% |
| Media & Publishing | 22.1% |
| Real Estate | 15.7% |
| SaaS & Technology | 16.2% |
| Travel & Hospitality | 13.4% |
| Nonprofit | 16.9% |
Overall average CTOR is 14% to 18%. A CTOR above 20% is strong, and above 25% is excellent.
How to Improve CTOR
- Align content with expectations: If your subject line promises a guide to email automation, deliver exactly that. Mismatched expectations kill clicks.
- Streamline your message: Remove unnecessary text and images. Make the path to the call-to-action as short as possible.
- Use a single primary CTA: Multiple competing calls-to-action reduce click rates. Choose one main action and make it obvious.
- Personalise content beyond the name: Use behavioural data to recommend relevant products, content, or offers.
- Optimise for preview panes: Many email clients show a preview pane. Ensure your key message and CTA are visible without scrolling.
- Test content formats: Experiment with plain text vs HTML, long-form vs short-form, and different image-to-text ratios.
Example Calculation
If your campaign has 1,960 unique opens and 320 unique clicks:
CTOR = (320 / 1,960) × 100 = 16.33%
This CTOR of 16.33% is near the cross-industry average. It means about 1 in 6 people who opened the email went on to click a link.
Related Glossary Terms
A/B Testing
A/B testing in email marketing is the practice of sending two variations of an email to a small sample of your list to determine which version performs better before sending the winner to the remaining subscribers.
Abandoned Cart Email
An abandoned cart email is an automated message sent to customers who added items to their online shopping cart but left without completing the purchase. It is one of the highest-converting email types in ecommerce.
Abuse Complaint
An abuse complaint is a report from a recipient who marks an email as spam, which negatively affects sender reputation and deliverability.
AIDA Model for Email
The AIDA model (Attention, Interest, Desire, Action) is a classic copywriting framework used to structure email campaigns that guide subscribers from awareness to conversion.
AMP for Email
AMP for Email is a Google-developed framework that allows email messages to include interactive elements like forms, carousels, accordions, and live content. It turns static emails into dynamic, interactive experiences directly inside the inbox.
Anchoring Effect in Email Marketing
The anchoring effect is a cognitive bias where the first piece of information presented (the anchor) influences subsequent decisions, used in email to frame pricing and value perception.
Frequently Asked Questions
CTOR (click-to-open rate) measures clicks divided by opens. It tells you how engaging your content is for people who already opened the email. CTR (click-through rate) measures clicks divided by delivered emails. CTR is affected by deliverability and subject line performance, while CTOR isolates content effectiveness.
CTOR is important because it removes the influence of subject line quality and deliverability from your content performance analysis. If your open rate is low but your CTOR is high, your content is good and you should work on subject lines and sender reputation. If your open rate is high but CTOR is low, your content needs improvement.
A CTOR between 15% and 20% is good for most industries. Below 10% indicates your content is not compelling enough for the people who opened. Above 25% is excellent and suggests strong content-to-audience alignment.
Focus on content relevance, clear CTAs, and mobile-friendly design. Use personalisation beyond first name — recommend products or content based on past behaviour. A/B test button copy, placement, and colour. Reduce the number of links per email to avoid choice paralysis and direct attention toward your primary CTA.
Yes. Mobile CTOR is typically 10-20% lower than desktop CTOR because of smaller screens, slower load times, and more distractions. However, since the majority of opens now happen on mobile, optimising for mobile CTOR is essential. Use single-column layouts, larger tap targets, and concise copy to improve mobile CTOR.