Work out your spam complaint rate in seconds. Enter how many complaints you got and how many emails were delivered, and see the rate plus whether it's under Google's 0.1% target, worth watching, or past the 0.3% ceiling. Runs right here in your browser.
Spam complaint rate calculator
0.120%complaint rate
Watch. Between the 0.1% target and the 0.3% ceiling - tighten opt-in and unsubscribe before it climbs.
Bands: under 0.1% healthy, 0.1-0.3% worth watching, over 0.3% risky. The 0.1% target and 0.3% ceiling are Google's published guidance - one send over the line is a warning, a sustained rate over it is what gets mail filtered or blocked.
How the complaint rate is calculated
The formula is simple: (complaints ÷ delivered) × 100. Deliver 10,000 emails, get 12 complaints, and your rate is 0.12%. Mailbox providers watch this number closely because a “report spam” click is the strongest signal that people don't want your mail, so the thresholds are far tighter than for bounces. See what a spam complaint rate is for the full picture.
Under 0.1%: healthy
Below Google's target, where a careful, opted-in sender should sit.
0.1-0.3%: worth watching
In the warning band. Make your one-click unsubscribe obvious so people opt out instead of reporting spam.
Over 0.3%: risky
Past Google's ceiling, high enough to get mail filtered or blocked. Set up feedback loops so you can suppress complainers fast.
Spam complaint rate calculator FAQ
Divide the number of spam complaints by the number of emails delivered and multiply by 100: (complaints ÷ delivered) × 100. Send 10,000 that reach the inbox and get 12 complaints, and your rate is 0.12%. Use delivered rather than sent as the denominator. That's the population that could actually have hit 'report spam'.
Google's published guidance is to keep your rate under 0.1% and never let it reach 0.3%. Under 0.1% is healthy, 0.1-0.3% is a warning band worth acting on, and a sustained rate above 0.3% is high enough to get your mail throttled, filtered to spam, or blocked outright. Lower is always better. The best senders sit well under 0.1%.
Google Postmaster Tools reports a spam rate for Gmail traffic directly, and most email platforms surface a complaint or 'marked as spam' count per campaign. The most reliable source is a feedback loop, where mailbox providers forward each 'report spam' click back to you so you can suppress that address.
Only mail people who genuinely opted in, make the unsubscribe link obvious so recipients leave without hitting 'report spam', honour opt-outs immediately, and keep sending frequency predictable. Verifying and cleaning your list also helps. Old, unengaged, or purchased addresses complain far more often than recent opt-ins.
Fewer complaints start with a clean list
Verify your list to remove the stale, unengaged addresses that complain most. Start free with 100 credits, no card required.
