Email marketing

What is CTOR & how to calculate it 

Email remains a formidable force in the world of digital marketing — but knowing how to measure the success of an email campaign through metrics is key to understanding just how well you’re taking advantage of the power of email.

Among the many metrics, none is as important as the Click-to-Open Rate (CTOR). 

Whether you are a seasoned email marketer or just starting out, these tips will help you optimize your email campaigns for better results. 

What is Click-to-Open Rate (CTOR)

CTOR is a metric used to calculate the percentage of people who opened an email and then went on to click on a link within it. At its core, CTOR illustrates the efficacy of the email content and the engaging power it holds over the recipients.

CTOR should not be confused with the similarly named Click-Through Rate (CTR).

The main purpose of CTR is to measure the ratio of clicks to impressions of an online ad or email marketing campaign. On the other hand, according to ImpactPlus, “CTOR stands for the click-to-open rate and compares the number of people that opened the email to the number that actually clicked.”


Source: TOAG

Neither metric is more important than the other — they simply track and represent two totally different things.

How to Calculate CTOR

Calculating the Click-To-Open Rate (CTOR) involves a straightforward method.

First, take the total number of unique clicks on your email and divide this by the total number of unique opens. Multiply the resulting figure by 100 to get your CTOR in percentage.

For example, imagine your email reaches 1,000 subscribers. Suppose 30 open it, and out of those, 18 click on something. The calculation for CTOR would be (18/30) * 100, equating to a 60% CTOR. This indicates a strong engagement rate among those who opened the email.

Remember, it’s crucial to consider only unique interactions. If a subscriber opens and clicks in the morning, and again in the evening, they should be counted just once. This ensures the data’s integrity, as the CTOR calculation is based on unique opens and clicks only.

What is good CTOR

The average CTOR across all industries is 11% in 2023. Translated into numbers, this means that for every ten people who open an email, one person clicks on whatever link you’re including in the body of the email. , meaning roughly one consumer clicks on the link inside the email out of every ten emails opened. 

Keep in mind, however, that there’s no magic, one-size-fits-all number for what a good open rate or click-through rate is for email. In most cases, it depends on your industry.

While the average for all industries is 11%, this doesn’t mean that number applies to you. For example, real estate, construction, and design industries see the highest CTOR averages at 17.7%, while food and beverage brands experience the lowest CTOR at 8.9%. 

So a good way to figure out what numbers you’re looking for is to see what the average is for your industry and then try to beat it.


CTR (Click-Through Rate) and CTOR (Click-To-Open Rate) are two different metrics used to evaluate email campaign effectiveness. 

  • CTR measures the percentage of email recipients who click on a link within the email relative to the total number of emails delivered. 
  • CTOR, on the other hand, calculates the percentage of clicks compared to only the emails that were opened. 

For example, if an email (Email A) is sent to 100 people, 20 open it, and 10 click a link, the CTR is 10% (10/100), while the CTOR is 50% (10/20). 

A different email (Email B) with 50 opens and 20 clicks from 100 recipients would have a CTR of 20% and a CTOR of 40%. 

These metrics can indicate different aspects of an email campaign’s success and areas for improvement.

Which metrics are the most useful

Closely analyzing your click-to-open rate can significantly bolster email marketing strategies.

When you understand subscribers’ behavior, you can make changes to enhance engagement and content personalization for increased sales and conversions.

Gauging Engagement

Understanding the behaviors and preferences of your subscribers is gold in email marketing.

When you understand what your subscribers want and are excited about, you can then craft content that resonates well with your audience.

Once you have a clear understanding of what makes your audience click, tailoring content that strikes a chord becomes more attainable.

According to digital group Vendilli, content engagement does three main things

  • Gets people thinking about your brand and helps build brand awareness 
  • Encourages customer loyalty so people are likely to come back for more at a later time 
  • Encourages people to share and discuss (helping spread the word about your brand)

Impact on Sales and Conversions

Email marketing has a potential ROI of $42 for every dollar spent — a jaw-dropping number that highlights the importance of tracking how well your campaigns are doing.  

CTOR plays a crucial role here. When potential customers are nurtured through personalized and engaging content, your conversion rates grow, leading to more sales over the long term. 

TIP: Read more about The True Costs of Email Marketing in our comprehensive article.


5 strategies to improve click-to-open rate

1. Crafting Compelling Subject Lines

According to Walsworth, 33% of people make a quick decision on whether to open an email based on the subject line alone, and 69% will report an email as spam based solely on the subject line.  

Even more importantly, personalized subject lines generate six times higher transaction rates than non-personalized subject lines. 

These statistics underscore the vital impact of subject lines on boosting the click-to-open rate (CTOR), influencing email open rates, steering clear of spam flags, and enhancing overall engagement. 

This personalization doesn’t have to be complicated either — something as simple as Including the recipient’s name or other relevant information can improve engagement. 

TIP: Not sure how well your subject lines are doing? Check out these 10 Subject Line Tester Tools That Can Help Boost Your Email Open Rate

2. Curating Engaging Content

Crafting the ultimate email requires a combination of great copy, attention-grabbing lines, and attractive CTAs.

Making that happen will ensure that your content resonates with the readers’ expectations and preferences. Even more importantly, by consistently delivering content that presents fresh perspectives, you set the stage for a relationship with your audience.

This is where the click-to-open rate (CTOR) begins to soar.

3. Mobile Optimization

More and more mails are being designed with a mobile-first approach, and for good reason.

Statistics show that a majority of email views now come from mobile devices (41%), followed by desktop (39%). Given such big numbers, imagine what happens if you open an email and the design is so off that you lose any interest in clicking anything. 

The result? The click-to-open rate worsens. 

Research conducted by MailChimp shows that “responsive email design … which adapts to different devices and screen sizes get higher click rates on all devices… particularly effective on mobile users, where the increase in unique clicks from 2.7% to 3.1% represents a 15% increase in actual clicks.”  

Optimizing elements such as layout, font size, and image dimensions can ensure a seamless mobile viewing experience, leading to a higher CTOR.

4. Segmenting Your Audience

Lastly, segmenting your audience forms the cornerstone of a successful email campaign. Understanding the varied needs and preferences of your audience segments can pave the way for content that resonates profoundly with each group. 

According to Zapier, “Email segmentation is the practice of breaking your email recipients into smaller, targeted groups and then sending them the most relevant information.” These smaller groups are usually based on behavioral or demographic data, including: 

  • state of residence
  • gender
  • marital status
  • occupation
  • a past purchase 
  • active versus inactive subscribers
  • what the person has clicked on your site before (or what pages they visited)

Through segmentation, you can foster a more personal connection with customers, which will result in a higher CTOR.

5. Cleaning Up Your Email List

A clean list improves your CTOR, enhances deliverability, and boosts engagement rates. 

List hygiene involves regularly updating your email list by removing inactive or non-existent email addresses and re-engaging dormant subscribers.

Inactive subscribers are “a huge issue in email marketing because the average list’s inactive rate is around 60%,” according to marketing guru Neil Patel. “This means that a list of 10,000 has only 4,000 true subscribers reading the posts.”

Clean up your email list 

Common mistakes and how to avoid them

On your journey to crafting email campaigns with higher CTOR, watch out for a few bumps in the road that could slow you down!

?Overloading emails with content. Avoid inundating your audience with information and instead focus on a balanced narrative that keeps them engaged and eager to keep reading.

?Neglecting email optimization. The same email doesn’t look the same on a PC vs. a phone vs. a tablet. If you’re not optimizing for mobile devices, you might be losing out on an important segment of your audience, resulting in lower CTORs.  

?Ignoring the power of A/B testing. How would you know what works if you don’t test different options? A/B testing basically means splitting your mailing list (could be different ratios e.g. 50/50 or 70/30) randomly and sending each group a slightly different version of the same email. This allows you to see the impact of a particular change – whether it’s in the subject line or within the email’s body — on your campaign’s click-to-open rate.


For professionals trying to make the most of their email marketing strategies (and who isn’t?), embracing CTOR as a central monitoring element can lead to campaigns that not only engage but also captivate.  

Improving click-to-open rates for emails is not a one-time thing, it requires constant testing and optimization so you can figure out what works and what needs to be addressed.

Remember, understanding your audience, crafting compelling subject lines, designing engaging email content, and optimizing for mobile devices are all crucial elements in improving click-to-open rates. 

Put these strategies into action and watch your email performance soar!

Diana Bocco

Written by

Diana Bocco

Diana is our go-to expert in email list verification at ELV. With a knack for turning complex challenges into simple solutions, Diana has spent years making sure businesses reach their customers without a hitch. She's all about clean, efficient communication, thanks to verified email lists that cut through the noise.

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