What is unsubscribe rate?
Unsubscribe rate is the share of recipients who opted out of your emails after a send. It is a direct, honest signal of whether your sending matches what people expected when they signed up. Some unsubscribes are healthy. They remove people who were never going to engage, which actually improves the quality of your list and your deliverability over time.
The formula.
Unsubscribe rate = (unsubscribes divided by delivered) times 100. Count opt-outs against the emails that were delivered, over a single send or a defined period. Track it per campaign as well as overall. A spike on one send points to that message; a steady climb points to frequency or relevance across the program.
A worked example.
Of 2,000 delivered emails, 6 people unsubscribe. The unsubscribe rate is 6 divided by 2,000, times 100, which is 0.3%.
What is a good unsubscribe rate?
Under 0.5% is healthy for most email programs. Between 0.5 and 1% is elevated and usually means you are sending too often or to people the content does not fit. Above 1% is a clear signal to step back and reassess.
How to lower it.
Send less but more relevant, segment so people get what they care about, and set frequency expectations at signup. Let people choose what and how often they hear from you instead of leaving.