Unsubscribe Rate
Quick definition
Unsubscribe rate is the percentage of delivered emails that resulted in the recipient unsubscribing.
Formula
Unsubscribe Rate = Unsubscribes ÷ Emails Delivered × 100
Formula variables
- Unsubscribes
- Recipients who unsubscribed from the send.
- Emails Delivered
- Emails accepted by recipients' mail servers.
Worked example
- Emails delivered
- 10,000
- Unsubscribes
- 20
20 ÷ 10,000 × 100
Result: 0.2%
Two in every 1,000 delivered emails led to an unsubscribe. The figures are illustrative, not a benchmark.
How definitions differ
- Per send or over time
- The rate is usually calculated per send. Cumulative list loss over a period is a different measure.
How to interpret it
Unsubscribes are a signal of relevance, frequency and expectation mismatch. A spike after a particular campaign or segment change points to what recipients disliked.
A low rate is not always good: it can also mean people are ignoring or marking messages as spam rather than unsubscribing. Read it alongside bounce and complaint rates.
When it is useful
- Monitoring list health.
- Testing send frequency and segmentation changes.
- Finding campaigns that disappoint expectations.
Limitations
- Some people stop engaging without unsubscribing.
- The base (delivered or sent) varies by platform.
- It does not show why people left.
Common mistakes
- Treating a low rate as proof that content is relevant.
- Comparing sends of very different sizes.
- Making unsubscribing hard, which pushes people toward spam reports.