How is unsubscribe rate calculated?
Still have a question, spotted an error, or have a better explanation or a source we should cite?
Unsubscribe rate is the percentage of delivered recipients who opted out after a specific campaign.
The formula: unique unsubscribes / delivered messages x 100.
Delivered means accepted by the receiving server, not bounced. So if you sent 10,000 emails, 500 bounced, and 50 people unsubscribed: 50 / 9,500 x 100 = 0.53% unsubscribe rate. Some ESPs calculate it slightly differently (sent vs delivered), so check your platform's definition to know what you're looking at.
What's a normal rate?
Under 0.5% per campaign is the general benchmark for a healthy list. Between 0.5% and 1% is worth watching. Consistently above 1% usually points to a mismatch: wrong audience, wrong frequency, or content that doesn't match what people expected when they signed up.
What the rate actually tells you
Unsubscribe rate is a lagging indicator. By the time someone unsubscribes, they've usually been quietly unhappy for a while (maybe ignoring you, maybe marking spam). A low unsubscribe rate doesn't mean everyone's happy. It might mean they've stopped opening entirely.
Watch the trend more than the absolute number. A sudden spike after a specific campaign tells you something about that campaign. A steady climb over months tells you something about your list strategy overall.
If unsubscribe rates are rising and you want to understand why, the SOS hotline is free.
Contributors
Who worked on this answer
Every name links to their profile. Every company links to their site. Real people, real accountability.
