Top 15 Email Marketing KPIs [Metrics and Formulas]

Padma Ramakrishna | Last Updated : 10 Nov, 2021

Many companies try to gauge email marketing effectiveness purely on open and click-through rates. But there are a lot more data to analyze. Depending on your objectives, there are several metrics you should be measuring. Several organizations refuse to believe in the power of email marketing. But more often than not, these companies feel that way because they aren’t measuring the right KPIs.

In this article, we’ll discuss 15 essential email marketing KPIs with examples and formulas to measure them. But if you’re wondering – to email or not email, get your answers from the following statistics.

Email marketing statistics

Top 15 Email Marketing KPIs

1. Email Deliverability Rate

The ability to deliver emails successfully to a subscriber’s inbox is email deliverability. We find the probability of campaigns reaching a customer’s inbox using this KPI. Email deliverability rates are critical and several KPIs depend on deliverability. If you’re experiencing low email deliverability, these are factors that reduce deliverability:

  • Sending without custom authentication
  • Utilizing single opt-in
  • Sending from a free domain email address
  • Making it tough to unsubscribe
  • Low levels of engagement

Your email deliverability rate should be as high as possible. It is because receiving servers send error messages to email service providers. These messages (ESPs) show why a message bounced in terms of delivery. To calculate your deliverability rate, use this formula: 

Email deliverability rate = Emails delivered ÷ Emails sent X 100 

Email deliverability rate formula

This is the first KPI to measure when assessing your email marketing campaigns. The secret to getting your emails read and acted on is getting them into the inbox. Tracking the Acceptance Rate alone isn’t enough to determine this. It does not mean that an email got delivered to the inbox only because the ISP accepted it and did not bounce back. As a vital email KPI, you should simultaneously track the Inbox Placement Rate.

2. Email Open Rates

Once upon a time, this was an important email marketing KPI to understand how well your campaign worked. But there have been ongoing debates about the relevance of email-open rates in recent times. With Apple’s new data privacy update with IOS 15, many argue that the email open rate KPI is bound to die.

This rings true across the United States and areas where Apple dominates because there is no way of measuring email-open rates as every mail will show up as opened by the recipient. It thus makes email-open rates obsolete to many in the US. However, you shouldn’t feel alarmed or anxious because emails are not dying – only open rates are.

You have several other key performance indicators that help measure your success. Emails are rich in data and provide several metrics for analysis, so you’ll have your hands full. As the IOS 15 will mask open rates, it will be pointless to try and measure it. Instead, use the following KPIs, track your deliverability and segment lists consistently.

By personalizing the subject lines and email content, we were able to increase the open rates by 327.75% and click rates by 543.75%.

Shibani Roy, Senior Manager – Brand Communications, LeadSquared.

[Also read: Email Marketing Best Practices I Learnt After Sending 2,049,567 Emails]

3. Click Through Rates

The click-through rate (CTR) is the percentage of people who view a web page and click on an ad on that page. Click-through rates are a metric well-loved by digital marketers. A click-through rate is a metric that compares the number of people who click on a given link, which is then divided by the number of people that view the webpage, mail, or ad (impressions).

The formula to measure ad CTR is:

CTR = Clicks ÷ Impressions X 100 

An email campaign’s CTR measurement is slightly different and uses the following formula:

Email CTR = Clicks ÷ (Emails sent – Bounces) x 100

calculate email CT R formula

An example of this would be receiving 30 clicks after sending 75 emails. Let’s assume 25 emails bounce so the CTR percentage would be 60%.

This click indicates whether your campaign was interesting enough to entice an open. Additionally, it helps track whether you receive a response from your audience.

Note that CTR benchmarks differ across industries

Emails in the business and finance field, for instance, may have a CTR of 2.59 percent. Conversely, emails in hobbies may have a CTR of 4.78 percent. The purpose of tracking click-through rate (CTR) is to measure levels of engagement. The higher the CTR, you will experience greater success in engaging your audience. 

4. Unsubscribe Rate

Unsubscribe rates may feel scary to assess and bring about feelings of doubt. But, much like other crucial KPIs, it will help you improve and attract more customers. A higher unsubscribe rate can point out that you might be doing something wrong. In contrast, a low unsubscribe rate reassures you and signals your successful marketing.

If you have of late noticed higher unsubscribe rates, these may be some reasons for it:

  • Lack of segmentation, which generally helps in sending relevant targeted content.
  • Low levels of readability on mobile and irrelevant content.
  • Overloading their inbox with emails can cause fatigue and irritate the customer.

If you aren’t segmenting your email lists, start now.

Apart from that, take the following measures to reduce the unsubscribe rate. 

  • Segment subscribers based on criteria that fit your ideal customer. Don’t sell to people who have never shown any interest in your product.
  • As much as you can personalize your pitch, ensure that what you send is relevant to them,
  • Make your emails mobile-friendly and consistently follow up with requests for feedback. 

CRM and Marketing Automation software such as LeadSquared helps you segment leads based on your chosen criteria. It also allows creating automated drip campaigns to nurture your leads.

Lead Segmentation - real estate CRM Software

Finally, SmartInsights found that an unsubscribe rate of less than 0.5 percent is normal. Anything below 02% is outstanding. So, if you fall under these numbers, you’re good to go. If not, it’s time to start looking into making that rate reduce.

5. Conversion Rate

Most marketers would agree that this email marketing KPI matters the most. In a way, they are right because your conversion rate is a direct metric to assess the success of your campaign.

The conversion rate is dependent on the number of people who complete a call-to-action. Every email campaign you create should propel your customers to perform some action.

It doesn’t mean that all emails need to include a CTA. But conversions are directly related to your sales and your customer’s buying intention. If your conversion rate is low, it can prove to be troublesome for your sales. So how do you measure conversion rates, and how can you increase that rate?

The formula for conversion rate:

Email conversion rate = Number of recipients that performed the CTA ÷ Number of emails sent X 100

email conversion rate formula

Below are the ways to increase conversion rates: 

  • Customize, personalize, and push for engagement in every email campaign. 
  • Keep your subject lines crisp and short. This helps improve mobile readability and reduces the chances of them losing interest.
  • Your CTA should be visible, if possible, as a button in a contrasting color. This guarantees that your recipient won’t miss it while reading.
  • Automate your campaigns and create workflows that get triggered by specific actions. 

These are some steps to increasing your conversion rate. A low conversion rate can be just as scary as a high unsubscribe rate. But finding ways to fix it and implementing them can help solve these issues. 

6. Email Bounce Rate

When you’re sending off campaigns serenely, this rate looms in the not-so-distant future. Your email bounce rate, similar to the unsubscribe rate, is a difficult-to-digest number. An email bounce rate signifies the number of emails that failed to reach recipients. When you receive a Non-Delivery Report (NDR) for an email, it shows that the email has bounced. We find the percentage of bounced emails by using the following formula:

Email bounce rate = Number of emails that bounced ÷ Number of emails sent X 100

email bounce rate formula

These email bounce rates show three types of bounces. You can either receive a hard, soft or pending bounce.

  • Invalid email addresses are the most common cause of a hard bounce.
  • Soft and pending bounces signal technical issues with the user’s or sender’s email service.

So, figuring out which type it is can help you gain clarity about your bounce rate. A high bounce rate shows that several emails you’ve sent never reached the recipients. This ends up diluting your company’s message and damaging relationships with valuable contacts.

You can follow these steps to decrease your bounce rate:

  • Consistently clean your lists and get rid of inactive recipients as much as possible. 
  • Don’t send emails that may sound like spam accounts. I’m sure you’ve received several spam emails. Use them as a guide on what not to do.
  • A/B test your campaigns as frequently as it will help you get an idea of what performs better in bounce rates.

Your bounce rates are also heavily dependent on your segmentation capabilities. So, ensure that you have lists that help you reach your intended recipient. And get rid of the IDs that continuously bounce.

7. Rate of Email Shares or Email Forwarding Rate

A high number of forwards of an email campaign can always put a smile on our face. Forward rates are the number of recipients who clicked on the share button within your email. Your customers typically forward these emails to friends and acquaintances. It may not appear as a significant indicator, but it is something to strive to improve. If your leads forward your emails, it suggests they are brand ambassadors who drive sales. They can help you reach new leads and boost lead generation in general.

Below is the formula to calculate email forwarding rates:

Email forwarding rate = Number of clicks on the share button ÷ Number of delivered emails x 100

email forwarding rate formula

Developing brand ambassadors through email marketing is a great strategy. 81% of consumers follow their friends’ social media posts when making purchasing decisions. Whatever your next campaign is, try to make it shareable. Something you would want your friends to see that’s fun and interactive. 

8. Revenue Per Email Subscriber

The ROI will show you your overall return on investment. But looking at the income per email will show you the success of your email campaign. Using this metric, you can quickly determine which emails are the most effective. It can also assist you in identifying issues that are lowering the overall ROI.

In contrast, revenue generated by each subscriber shows you their worth. It is critical since it enables you to determine the quality of your email list. It will also help in accurately describing your ideal subscriber persona.

Following is the formula for revenue per email:

Revenue per email = Revenue from each email ÷ Number of sent emails

revenue per email formula

The formula for revenue per subscriber:

Revenue per email subscriber = Total revenue generated ÷ Number of subscribers

revenue per email subscriber formula

These calculations help you delve into the nitty-gritty of your revenue while giving you insights into the innate value of the subscribers in your list.

First, you must find the subscribers who provide the highest value. Then, you can search for more people who have similar traits. This approach will help you increase your revenue over time. 

9. Email ROI 

Return on investment (ROI) is a metric to assess an investment’s profitability. It is an indicator of the efficiency of an email marketing campaign in this scenario. Measuring email ROI seems straightforward. But you must consider your email marketing goals before you measure them. 

For example, we create campaigns for different reasons like:

  • To increase engagement and nurture leads.
  • Boost revenue and increase overall sales.
  • Increase brand awareness and create a positive image.

Once you categorize your campaigns under these areas, you can measure your ROI. For instance, email campaigns created to boost revenue must be measured in terms of ROI. But ROI might not be the right email marketing KPI for brand awareness campaigns

Use this formula to calculate your ROI from email campaigns:

Email ROI = (Revenue gained – Amount invested) ÷ Amount invested

Email ROI formula - Email marketing KPIs

If your gains are lesser than the investment, it’s time to figure out how to increase profits. Some ways to boost ROI from emails are:

  • Create clear goals with a plan of action to assess ROI comprehensively.
  • Try to push for more growth in your email lists. 
  • Check your deliverability rates and ensure that your emails don’t end up in the spam folders.

ROI is an indicator that is easy to get caught up in. It feels a lot more important, and, in a way, it is. But it isn’t the only measure of success. So, don’t feel down if it is lower than expected, instead focus on improving the mentioned email marketing KPIs, and you’ll naturally increase your ROI.

10. Spam Complaint Rate

Spam complaint rate is a crucial indicator of whether you’re helping customers. A highly segmented list will reduce the number of spam complaints. In contrast, a lack of appropriate segmentation can cause considerable harm. Any spam complaint rate of less than 0.1 percent is acceptable across industries. Anything higher than this number is not a good indicator. Major inbox providers, such as Gmail, have established this as the industry standard.

You can calculate your spam complaint rate with this formula:

Spam complaint rate = Number of spam complaints ÷ Number of sent emails X 100

spam complaint rate formula - email marketing KPIs

For example, if you receive 7 complaints after sending 7000 emails, you have a rate of 0.1%. 

Ensure that this rate stays as low as possible. You can follow these tips to reduce your spam complaint rates:

  • Use double opt-in or add a clear captcha in your forms. It will increase the level of confirmation from your recipient’s side.
  • Keep the option to unsubscribe in a visible spot. Unsubscribing, unlike spam complaints, won’t hurt your deliverability.
  • Send the emails through the specific domains your leads signed up within. It reduces any feelings of confusion or frustration. 

Your spam complaint rate can feel overwhelming if it’s high. But it is easy to lower this rate once you actively look into this email marketing KPI. Whatever the rate is, ensure that it doesn’t create a negative impact on your brand.

11. List Growth Rate

Your list growth rate shows the rate at which your subscriber base is growing.

It’s critical to determine if and how fast your mailing list is increasing. If your rate is low, or worse, negative, you should rethink your lead generation strategies.

In contrast, when you experience increased growth, ensure that your engagement stays strong. List growth goes hand in hand with greater forwards and shares. So if you want your lists to grow organically, make sure that you create shareable content.

Content that is widely appreciated will naturally help your list growth rate improve, whereas you will see negative numbers when your content fails to engage your leads.

List growth rate = (Number of new email subscribers – number of people who unsubscribed) ÷ total number of email IDs X 100

email list growth rate formula

You should track your list growth and attrition in addition to the call-to-action metrics. Also, you must strive to develop your mailing list to expand your influence. It will help diversify your audience and establish yourself in your industry.

12. Subscriber Lifetime Value 

The lifetime value of an email subscriber is similar to the lifetime value of a customer (CLV). We take the lifespan of the email subscription and the impact your emails make at that time rather than just the lifetime of the customer relationship.

Subscriber lifetime value (SLV) shows the positive influence you’ve had on your customers. It gives insight into the value of your email campaigns in the life of the average subscriber. 

The formula to calculate subscriber lifetime value for a month will differ from the SLV for a year.

To calculate email subscriber lifetime value,

  • First, find your monthly revenue from the list of emails.
  • Second, subtract the extra expenses from that number.
  • Third, divide that amount by the number of subscribers you had in that month.

The formula for a year is far more intricate and time-consuming. Read this article to understand what steps you need to take to measure yearly SLV. A healthy SLV shows that you’re on the right track over long periods. It can be difficult to measure but will help you define goals for the future. Combine lifetime value with ROI, and you have powerful metrics that help you revolutionize your email marketing. For most email marketers, this is a major step forward.

[Resource: Learn how to run high-performing email campaigns]

13. Engagement Levels Over Time

When you track engagement over time, you can figure out the optimum times to send emails. You can also use email marketing automation to streamline the lead nurturing process. You can use client behavior or action-based triggers and deliver mails. Tracking interaction over time shows when non-automated emails have the best click rates. 

Some email service providers automate this process and collect data on your behalf. But, tracking this parameter on your own and finding the ideal timings can boost growth. It may seem like an inconsequential KPI, but low engagement levels are a warning. If you don’t actively measure engagement rates, you’re missing opportunities. You can use the various email marketing KPIs on this list to help find areas to increase engagement. 

14. Click-to-Open Rate

CTOR or click-to-open rate gives you an understanding of your email campaign. It shows whether your email had any true value to the recipient as it measures the number of people who opened the email and clicked on the content within. 

CTOR is a helpful metric to gauge the effectiveness of your campaign in creating interest. Readers will click through to discover more if your links, design, and content is exciting. This metric depends on the number of unique opens. You must use these opens to divide the number of unique clicks you received. 

 A good click-to-open rate falls anywhere between 20-30% across industries. If you’re struggling to get a good CTOR, try the following steps to improve it:

  • Create content that is meaningful and valuable for readers. Even if you’re essentially selling a product, show your readers how the product will help.
  • Hyper-personalize your subject line, ad copy, product offers, and more. Don’t create a generic copy while expecting several unique clicks.
  • Test different kinds of content and analyze what gave a high CTOR. It will help you find a definite content recipe that works over time.

Much like all the other email marketing KPIs on this list, CTOR will help you create better content. Not just that, it will show you how effective your content is in receiving engagement. 

15. Inbox Placement Rate

The percentage of sent emails that made it to the intended inbox is the inbox placement rate (IPR). If your inbox placement rate is poor, it could be because of:

  • Irrelevant information,
  • Reputation issues with the IP address and/or domain,
  • Sending messages to faulty or unregistered email addresses regularly.

You will be able to interpret why your emails are being filtered into spam folders at this rate. As you can now assess what kind of content immediately gets sent to spam. And you can find what content works well in getting into the right inbox. The formula for IPR is:

Inbox placement rate = Emails that reached the right inbox ÷ Number of sent emails x 100

inbox placement rate formula

In Conclusion

These are the top 15 email marketing KPIs that every marketer should monitor closely. Some of these KPIs may be more useful to certain industries but can help no matter what sector you fall under.

While measuring your campaign’s success, opt for metrics that:

  • Help you actively collect data to analyze where you can improve.
  • Give you a deeper understanding of subscriber behavior and increase engagement.
  • Help your organization create reachable goals and strategies for the future.

However, an indispensable tool for every campaign is segmentation. Your metrics can help you measure every activity. But if you fail to segment your lists, all the KPIs in the world won’t help you improve. Additionally, automating your campaigns and ensuring that you include action-based triggers is a must. These can lighten the load on your marketing team and help you focus on each KPI. To measure your campaigns and automate them, use LeadSquared! LeadSquared CRM offers email automation, tracking, and reports to make your next campaign more effective.


Email Marketing KPIs FAQs

How do you measure email performance?

You can measure email performance by looking at the email KPIs or metrics. Some of the most popular ones are open rates, bounce rates, CTR, Conversion rates, unsubscribe rates, and more.

What are the best email marketing analytics tools?

There are many tools available in the market for email marketing automation and analytics. Some of the best ones are LeadSquared Marketing Automation, Mailtrack, SalesHandy, and MailTag.

What is the most important metric in email marketing?

There are several email marketing metrics crucial to determine your campaign performance and improve them. Read the article to understand the 15 most important email marketing metrics.

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