10 Important Email Marketing KPIs and How To Calculate Them

In the vast expanse of digital marketing, email marketing stands out as a time-tested, direct line to your audience. Understanding and leveraging email marketing metrics is not just beneficial—it's essential for the health and success of your campaigns. Email marketing KPIs (Key Performance Indicators) serve as the navigational stars for marketers, offering insights into the performance and effectiveness of their email campaigns.

This guide dives deep into the key metrics that will help you gauge success, engage more deeply with your subscribers, and drive your marketing goals forward.

Key Email Marketing KPIs to Monitor

Open Rate

The open rate represents the percentage of recipients who opened your email. It's a direct indicator of how well your subject line performs. Industry benchmarks vary, but a good open rate generally falls between 15% to 25%. Improving your open rates can be as simple as personalizing subject lines, segmenting your audiences, or sending emails at the optimal time for your audience.

Open Rate = (# of Emails Opened / # of Emails Delivered​) × 100%

Click-Through Rate (CTR)

CTR measures the percentage of email recipients who clicked on one or more links contained in an email. This metric is crucial for understanding how engaging your email content is. A higher CTR means more engagement. To boost your CTR, consider using compelling calls-to-action and ensuring your links are relevant and valuable to your audience. A good CTR is generally considered around 2.5-5%.

CTR = (# of Clicks / # of Emails Delivered​) × 100%

Conversion Rate

Arguably the most important KPI to monitor, conversion rates track the percentage of email recipients who completed a desired action, like making a purchase or signing up for a webinar, after clicking on a link in your email. Conversion rates help quantify the financial impact of your email campaigns. Optimizing emails for conversions can involve clear, concise messaging and a seamless user experience.

Conversion Rate = (# of Desired Actions Taken / # of Emails Delivered​) × 100%

Bounce Rate

Bounce rate refers to the percentage of your total emails sent that could not be delivered to the recipient's inbox. High bounce rates can damage your sender reputation. 

Be sure to note the difference between hard bounces and soft bounces. A hard bounce signifies a permanent problem, such as sending to an invalid or nonexistent email address. A soft bounce relates to a temporary issue, such as a full inbox or server being down. 

Bounce rates above 2% could indicate problems with your email list quality or sending practices. To reduce bounce rates, regularly clean your email list and verify email addresses before sending campaigns.

Bounce Rate = (# of Bounced Emails / Total Emails Sent) × 100%

Delivery

Email delivery rates refer to the ability of an email to successfully reach the recipient's inbox without being blocked by spam filters or rejected by the email server. It's influenced by factors such as sender reputation, email content quality, recipient engagement, and the health of the email list. 

Ideal Delivery: Above 95%

Acceptable Delivery: 90-95%

Poor Delivery: Below 90%

High deliverability means a greater portion of your emails reach your intended audience, directly impacting the effectiveness of your email marketing campaigns.

Low deliverability, especially due to high bounce rates or spam complaints, can result in your sending IP being blacklisted, significantly hindering your ability to send emails as they get blocked by ISPs and email service providers.

Advanced KPIs for Email Marketing

List Growth Rate

Your list growth rate is a testament to the vitality of your email marketing efforts. Growing your email list involves leveraging multiple channels and offering value in exchange for subscriptions, such as discount codes or valuable content.

List Growth Rate = ( # New Subs - # Unsubs / Total # Emails on List ) × 100%

Subscriber Lifetime Value 

​​Subscriber Lifetime Value (SLV) is calculated by combining the average revenue per subscriber, the average lifespan of a subscriber, and the conversion rate of your email marketing campaigns.

Subscriber Lifetime Value = Average Revenue Per Email × Number of Emails Opened Per Year × Average Subscriber Lifespan (years)

Active vs. Inactive Subscribers

Identifying the proportion of your list actively engaging with your emails versus those who haven’t engaged over a certain period can guide re-engagement strategies. It is also a good practice to remove, or “sunset”, completely inactive subscribers from your primary newsletter list. 

For active and inactive subscribers, it's more about segmentation than a single calculation. You segment subscribers based on engagement criteria, such as opening or clicking within a specific timeframe. For example, active subscribers might have opened an email in the last 3 months, while inactive did not.

Device Open Rates

This metric tracks which devices (mobile, desktop, tablet) your emails are opened on, helping to optimize for device compatibility and user experience.

Device Open Rate = (# of Opens on a Device / Total # of Opens) × 100%

Overall ROI of Email Marketing Campaigns

Measuring the ROI of your email marketing helps you understand the effectiveness of your campaigns in monetary terms. To maximize ROI, focus on personalization, segmentation, and targeted content that resonates with your audience.

ROI = (Total Revenue from Campaign - Total Cost of Campaign / Total Cost of Campaigns) × 100%

Reviewing these email marketing metrics is not a one-and-done task but rather something that should be done at minimum quarterly. Successful email marketers adopt a continuous process of testing, learning, and adapting. Employ A/B testing to refine your approach based on solid data, and don't shy away from using advanced tools for deeper insights into your campaign's performance.

By understanding and acting on these metrics, you can ensure your email campaigns resonate with your audience, drive engagement, and contribute to your overall business goals.

Looking for more interactive marketing metric calculators? Check out our Calculators page.