What is error budget burn rate?

Burn rate measures how quickly you are consuming your error budget relative to how quickly time is passing. A burn rate of 1.0 means you are consuming your budget at exactly the rate that would exhaust it at the end of the window — perfectly on pace. A burn rate of 2.0 means you are burning budget twice as fast as sustainable.

Google's SRE book recommends alerting at burn rates of 14.4× (for a 1-hour alert) and 6× (for a 6-hour alert) to catch incidents that would exhaust a 30-day budget in 2 hours or 5 hours respectively.

Burn rate > 1.0 means your error budget will be exhausted before the window ends if the current rate continues. Burn rate < 1.0 means you have headroom.

What to do when budget is low

When error budget drops below 10–20%, most SRE teams trigger a reliability review and consider freezing non-essential deployments until the budget recovers. The specific threshold should be defined in your team's SLO policy before it becomes urgent.