What are the formulas behind the email metrics we all rely on? How do you account for bounces when calculating metrics? Do you use unique or total quantities? These and other answers await you in this blog post.
Last month I wrote about internal benchmarks – I’ve received a lot of good feedback, as well as questions about the formulas behind the metrics calculations. So I thought I’d provide this companion post.
Many marketing platforms calculate your metrics for you. That’s great. But… not all platforms use the same formulas or the same names for those metrics. Even if you aren’t calculating them yourself, it’s important to understand the formulas your platform is using as well as the formulas considered standard in the industry.
Let’s jump in!
Overview
Here are the metrics we’ll cover:
- Bounce Rate
- Non-Bounce Rate
- Open Rate
- Click-through Rate (CTR)
- Click-to-open Rate (CTOR)
- Unsubscribe Rate
- Spam Complaint Rate
- Conversion Rate from Sent (CR from Sent)
- Average Order Value (AOV)
- Revenue-per-email-sent (RPE)
- Revenue-per-thousand-email-sent (RPME)
Notes:
- Formatting
- Most of the metrics are presented as percentages
- Exceptions are AOV, RPE, and RPME, which are presented as dollars or whatever currency you’re working with
- Rounding
- We round to one decimal point for most metrics
- Exceptions are Unsubscribe rate and spam complaint rate, where we round to two decimal points (this is due to the relatively small size of the value)
- Also exceptions: currency formats (AOV, RPE, and RPME) where we round to two decimal points as is traditional for currency values
We’ll also use the following raw data to illustrate how to calculate each metric:
We’ll use symbols for the formulas to ease with readability – here’s a guide:
- the ‘/’ symbol stands for ‘divided by’
- the ‘*’ symbol stands ‘multiplied by’
- The ‘-‘ symbol stands for ‘minus’
Bounce Rate
Formula: (Bounces / Send Quantity) * 100
Calculation (using raw data above):
(3,000 / 100,000) *100
0.03 * 100
3.0%
Additional Resources:
Here is an additional resource to help you leverage bounce rates.
Find more by using the search button (top right, in the header) on this blog.
Non-Bounce Rate
Formula: (Non-Bounce Sent / Send Quantity) * 100
Calculation (using raw data above):
(97,000 / 100,000) *100
0.97 * 100
97.0%
Additional Resources:
Here is an additional resource to help you leverage assumed delivered rates.
Find more by using the search button (top right, in the header) on this blog.
Open Rate
Formula: (Unique Opens / (Send Quantity – Bounces) * 100
Calculation (using raw data above):
(33,950 / 100,000 – 3,000) *100
(33,950 / 97,000) *100
0.35 * 100
35.0%
Additional Resources:
Here are some additional resources to help you leverage open rates.
- Apple’s Mail Privacy Protection: The Sky Isn’t Falling After All
- Why Open Rate Isn’t a Good Key Performance Indicator for Subject Line Tests
- Thoughts on Life Without Email Open Rates
- Leveraging the Email Marketing Funnel to Boost Your Bottom-line Performance
- Ten Numbers Every Email Marketer Should Commit To Memory
Find more by using the search button (top right, in the header) on this blog.
Click-through Rate (CTR)
Formula: (Unique Clicks / (Send Quantity – Bounces) * 100
Calculation (using raw data above):
(3,395 / 100,000 – 3,000) *100
(3,395 / 97,000) *100
0.035 * 100
3.5%
Additional Resources:
Here are some additional resources to help you leverage click-through rates.
- Proof That Click-through Rate is Not a Good KPI
- From the Boards: CTR or CTOR?
- A Simple Segmentation Strategy to Boost Revenue [Case Study with Data]
- The Honeymoon Effect: New Subscribers Click at a Rate 116% Greater than Existing Subscribers
- Leveraging the Email Marketing Funnel to Boost Your Bottom-line Performance
Find more by using the search button (top right, in the header) on this blog.
Click-to-open Rate (CTOR)
Formula: (Unique Clicks / Unique Opens) * 100
Calculation (using raw data above):
(3,395 / 33,950) *100
0.1 * 100
10.0%
Additional Resources:
Here are some additional resources to help you leverage click-to-open rates.
Find more by using the search button (top right, in the header) on this blog.
Unsubscribe Rate
Formula: Unsubscribes / (Send Quantity – Bounces) * 100
Calculation (using raw data above):
(100 / 100,000 – 3,000) *100
(100 / 97,000) * 100
0.00103093 * 100
0.10%
Additional Resources:
Here are some additional resources to help you leverage unsubscribe rates.
- How I Learned to Stop Worrying and Love Prominent Email Unsubscribe Mechanisms
- The Honeymoon Effect: New Subscribers Generate Higher Revenue Than Existing Subscribers (3,922% More!)
- Rethinking Email Resends
- The *Best* Way to Do Email Resends
Find more by using the search button (top right, in the header) on this blog.
Spam Complaint Rate
Formula: Spam Complaints / (Send Quantity – Bounces) * 100
Calculation (using raw data above):
(10 / 100,000 – 3,000) *100
(10 / 97,000) * 100
0.00010309 * 100
0.01%
Additional Resources:
Here are some additional resources to help you leverage spam complaint rates.
- The Honeymoon Effect: New Subscribers Generate Higher Revenue Than Existing Subscribers (3,922% More!)
- Rethinking Email Resends
- The *Best* Way to Do Email Resends
Find more by using the search button (top right, in the header) on this blog.
Conversion Rate from Sent (CR from Sent)
Formula: Conversions / (Send Quantity – Bounces) * 100
Calculation (using raw data above):
(1,455 / 100,000 – 3,000) *100
(1,455 / 97,000) * 100
0.015 * 100
1.5%
Additional Resources:
Here are some additional resources to help you leverage conversion rates.
- Case Study: Opt-in Email Lists Deliver Conversion Rates up to 21-times Those of Not-Opt-In Lists
- The Honeymoon Effect: New Subscribers Generate Higher Revenue Than Existing Subscribers (3,922% More!)
- 95% Boost in Conversions from a Small, Simple Change
- Leveraging the Email Marketing Funnel to Boost Your Bottom-line Performance
- The *Best* Way to Do Email Resends
Find more by using the search button (top right, in the header) on this blog.
Average Order Value (AOV)
Formula: Revenue / Conversions
Calculation (using raw data above):
$100,000 / 1,455
$68,73
Additional Resources:
Here are some additional resources to help you leverage average order values.
- Case Study: Optimizing to Avoid Analysis Paralysis
- A Simple Segmentation Strategy to Boost Revenue [Case Study with Data]
Find more by using the search button (top right, in the header) on this blog.
Revenue-per-email-sent (RPE)
Formula: Revenue / (Send Quantity – Bounces)
Calculation (using raw data above):
($100,000 / 100,000 – 3,000)
($100,000 / 97,000)
$1.03
Additional Resources:
Here are some additional resources to help you leverage RPE.
- Revenue per Email – An Advanced Email Marketing Metric You Should Know
- Case Study: 61% Decrease in Revenue-per-email (RPE), But We Still Learned a Few Things
- Case Study: 63% Lift in Revenue from a Simple Subject Line Test
- Case Study: Strategic Resend, 25% More Revenue
Find more by using the search button (top right, in the header) on this blog.
Revenue-per-thousand-email-sent (RPME)
Formula: Revenue / ((Send Quantity – Bounces) / 1,000)
Calculation (using raw data above):
$100,000 / ((100,000 – 3,000) / 1,000)
$100,000 / (97,000 / 1,000)
$100,000 / 97
$1,030.93
Additional Resources:
Here are some additional resources to help you leverage RPME.
- The Honeymoon Effect: New Subscribers Generate Higher Revenue Than Existing Subscribers (3,922% More!)
- A Tale of Two Purchased Lists (A Case Study)
- 43% Increase in Revenue with a Holiday Campaign! Here’s How We Did It…
Find more by using the search button (top right, in the header) on this blog.
Hope you found this helpful! If you’re looking for more help, whether it’s strategic/tactical consulting, a fractional email director/VP role, or workshop training, let’s chat!
jj
Photo by Mark Wilkinson Hughes on Unsplash
