The top email marketing metrics and KPIs to measure success

If you send an email out into the wild and don’t review the metrics, did it really happen?

Of course it did! But it does make it difficult to know what kind of impact your email had. Did a lot of subscribers open it? Did they click any links? Did they make a purchase as a result?


To answer these questions and discover if your emails are helping you connect with customers and grow your business, know which email marketing metrics and key performance indicators (or KPIs) to look for and why they are essential.

Open rate

Open rates measure the number of people who opened your messages. Your open rate can provide several insights into your email’s overall performance, including whether your subject lines are effective and the best times to email subscribers.

If your open rates aren’t as high as you want them to be, there are simple steps you can take to try to improve them. 

For example, try emphasizing urgency in your subject lines to make them more compelling. Or, add specific details that tell subscribers exactly what they’ll get in your emails. Your goal is to stand out in the inbox, so you need to convince subscribers that your content is worth engaging with.

Low open rates could also mean that you’re not sending emails at an ideal time for your subscribers. Try sending your emails on different days and times.

With this insight, you can identify how you can get more people to view your emails.

How to calculate your open rate

Open rates are calculated by taking the unique opens (i.e., the total number of unique subscribers who open your email) and dividing it by the total number of delivered emails. 

TOTAL UNIQUE OPENED EMAILS ÷ TOTAL EMAILS DELIVERED * 100 = OPEN RATE

Open rate calculation examples

If you send an email and it’s delivered to 1,000 subscribers and 300 of them open it, you would have a 30% open rate.

300 (Unique Opens) ÷ 1,000 (Emails Delivered) * 100 = 30% (Open Rate)

Click-through rate (CTR)

Your email click-through rate tells you whether or not your email content and call to action is relevant to your subscribers. 

If you find your subscribers are opening your emails but not clicking the links within them, there are a few actions you can take to fix this issue. 

For example, try different types of content. As you experiment with different types of content, make note of what works and what doesn’t. Create an email content calendar and keep track of the things your subscribers love most.

It’s also possible your low CTR is due to your call to action (CTA). Start testing different CTA copy to see if one works better than the other.

Segmenting subscribers and sending targeted emails can work wonders for improving the click-through rate in your emails.

The insight you gain from your click-through rate metrics can help you optimize the content of your emails. 

How to calculate your click-through rate

Similar to open rates, click-through rates are calculated based on unique clicks. To get a more accurate idea of how many subscribers are engaged with your emails, you’ll want to look at the total unique clicks (i.e., the number of subscribers who clicked on a link in your email) and divide it by the total number of recipients.

TOTAL UNIQUE CLICKS ÷ TOTAL EMAILS DELIVERED * 100 = CLICK-THROUGH RATE

Click-through rate example

If you send an email to 1,000 subscribers and 80 of them click on a link in it, you would have an 8% click-through rate.

80 (Unique Clicks) ÷ 1,000 (Emails Delivered) * 100 = 8% (Click-Through Rate)

Conversion rate

Your conversion rate is the percentage of subscribers who complete a goal from your email campaign. This is a very important email marketing kpi because it indicates how effective your campaign is performing.

Your conversion rate can be influenced by several factors:

  • Email segmentation – are you sending the right offer to the right subscribers?
  • Call-to-action (CTA) – is the CTA in your email direct? Are you using action terms?
  • Landing page – is your landing page optimized to get the visitor to take a desired action?

How to calculate your email conversion rate

Email conversion rates are calculated by taking the number of conversions (subscribers who completed the desired goal) and dividing that number by the total number of emails delivered.

CONVERSIONS (EMAIL GOAL) ÷ TOTAL EMAILS DELIVERED * 100 = CONVERSION RATE

Conversion rate example

If you send an email which is delivered to 1,000 subscribers and 5 of them completed your goal (conversion), then you would have a conversion rate of 5%.

5 (Conversions) ÷ 1,000 (Emails Delivered) * 100 = 5% (Conversion Rate)

Bounce rate

A bounce rate is a good indication on the health of your email list.

Bounce rates are broken out into two categories: hard bounces and soft bounces.

A hard bounce means a recipient’s email account is closed or invalid. Most email marketing providers will automatically unsubscribe someone who hard bounces.

A soft bounce means a recipient’s email account is temporarily unavailable. This typically happens when a server is unavailable or a recipient’s inbox is full. Most email marketing providers will continue to send to a soft bounce several times before automatically unsubscribing them from your email list.

Ideally, you want to aim for a bounce rate that is less than five percent. To do so, my advice is to maintain a clean, active and engaged email list.

How to calculate your bounce rate

Bounce rates are calculated by taking the total number of bounces and dividing it by the total number of emails sent. This is different from the other email marketing metrics as a bounce rate is being calculated off the total emails sent.

BOUNCED EMAILS ÷ TOTAL EMAILS SENT * 100 = BOUNCE RATE

Bounce rate example

If you send 1,000 emails and 50 bounced (were not delivered) then your bounce rate would be 5%.

50 (Bounced Emails) ÷ 1,000 (Emails Sent) * 100 = 5% (Bounce Rate)

Delivery rate

Your email delivery rate is the opposite of your bounce rate. If an email does not bounce then it is considered delivered.  However, just because an email is “delivered”, does not mean that it reached your recipient’s inbox.

If you find that your email open rates are unusually low and spam complaints are high, there may be an issue with deliverability, which influences whether or not your emails make it into your subscribers’ inboxes.

There are several factors that influence the deliverability of your emails, but the best way to maintain a good email deliverability rate is by adhering to the CAN-SPAM Act and email marketing best practices.

According to the CAN-SPAM Act, a U.S. law that regulates commercial emails, senders must:

  • Include a way for subscribers to unsubscribe
  • Contain the sender’s valid postal address
  • Be clear about who is sending the email
  • Label the message as an advertisement
  • Avoid misleading subject lines

How to calculate your delivery rate

Delivery rate is calculated by dividing the number of emails sent by the number of emails delivered. 

Your delivery rate is the opposite of your bounce rate. Meaning if an email didn’t bounce, then it was considered delivered. 

DELIVERED EMAILS ÷ TOTAL EMAILS SENT * 100 = DELIVERY RATE

Delivery rate example

If you send 1,000 emails and 950 were delivered (did not bounce) then your delivery rate would be 95%.

950 (Delivered Emails) ÷ 1,000 (Emails Sent) * 100 = 95% (Delivery Rate)

Unsubscribe rate

Losing subscribers is difficult for any email marketer to cope with. You want to have as many people on your list as possible, but you also want to send to people who truly want to hear from you.

Rest assured that unsubscribes are a normal and common part of maintaining a healthy email list.

There are many reasons someone may unsubscribe from your emails. Maybe your email content isn’t satisfying their needs anymore. Or perhaps you’re sending too frequently.

If more people are unsubscribing than they are joining your list, it might be time to re-evaluate your email content strategy and your open and click-through rates. If they’re low, you might need to see how you can send more relevant and compelling content

How to calculate your unsubscribe rate

Unsubscribed rate is calculated by dividing the total number of people who unsubscribed by the total number of emails delivered.

UNSUBSCRIBED EMAILS ÷ TOTAL EMAILS DELIVERED * 100 = UNSUBSCRIBE RATE

Unsubscribe rate example

If you send 1,000 emails and 10 people unsubscribed then your unsubscribe rate would be 1%.

10 (Unsubscribes) ÷ 1,000 (Emails Delivered) * 100 = 1% (Unsubscribe Rate)

Complaint rate (spam complaints)

A consistently high complaint rate can have serious consequences on your deliverability and potentially get you into trouble with your email marketing provider. Sticking to email marketing best practices will help you maintain a low complaint rate.

How to calculate your complaint rate

Your complaint rate is calculated by taking the total number of complaints and dividing it by the total number of emails delivered. Your goal should be to keep your complaint rate no higher than 0.1%.

COMPLAINTS ÷ TOTAL EMAILS DELIVERED * 100 = COMPLAINT RATE

Complaint rate example

If you send 1,000 emails and 1 person complains then your complaint rate would be 0.1%.

1 (Complaints) ÷ 1,000 (Emails Delivered) * 100 = 1% (Complaint Rate)

Email Marketing Return on investment (ROI)

Return on investment is used to calculate the effectiveness of an email marketing campaign. At the end of the day, if all your other email marketing metrics could be strong but if you’re not making a profit then you should look into your costs or your pricing model.

Are your costs high because you’re paying for email marketing and a landing page builder tools with different providers? If so, look to consolidate this with a single provider.

How to calculate your email marketing ROI

Email marketing return on investment (ROI) is calculated by taking the revenue earned from an email campaign, subtracting that amount by the amount spent, and finally dividing that number by the amount spent to get the ROI expressed as a percentage.

(REVENUE – SPEND) ÷ SPEND = ROI

ROI example

If your total cost for an email campaign was $100 and you earned $4,000, then the ROI would be $39. So you would earn $39 for every $1 spent.

$4,000 (Revenue) – $100 (Spend) ÷ $100 (Spend) = $39 (ROI)

Revenue per email

Tracking the return on investment from your emails is a simple and helpful way to track the success of your email marketing strategy.

As you identify which emails are driving the most revenue, you can make tweaks to your overall strategy to send more similar emails and optimize success. 

How to calculate your revenue per email

The revenue per email is calculated by dividing the revenue generated from a specific email campaign and dividing it by the number of emails successfully delivered.

REVENUE ÷ EMAILS DELIVERED = REVENUE PER EMAIL

Revenue per email example

If revenue from an email campaign was $800 and 1,000 emails were successfully delivered, then the revenue per email would be $0.80.

$800 (Revenue) ÷  1,000 (Emails Delivered) = $0.80 (Revenue Per Email)

How do you measure success of email marketing

You can measure the success of your email marketing by determining the right KPIs to focus on. Your email metrics tell you a story about your customer’s engagement. Use that intel to discover opportunities to make improvements, deliver more value and increase the effectiveness of your emails.

Which email marketing kpis should I focus on

You need to be focusing on each email marketing kpi. They all play an integral role in the performance of your email. The graph is an email marketing metrics funnel, it shows how each key performance metric could impact your overall performance. 

Funnel showing how each email marketing metrics is impacted by each other

For example, if your delivery rate or open rate are low, this will inevitably impact the available number of subscribers who would click on your email and ultimately convert.

Interpreting the data from your email analytics may seem daunting, but don’t be afraid to delve into it. You now have the information you need to focus your efforts

Like any other business strategy, analytics are the key to identifying success. 

Contributions: Monica Montesa and Brandon Olson