A service has a 99.9% SLO over 30 days. A bad deploy makes 1.44% of requests fail and stays out. If nothing changes, how long until the whole month's error budget is gone?

Answer

About 50 hours. In review, anything from 33.3 to 75 counts as right.

The worked estimate

The budget is 0.1% failures. 1.44% ÷ 0.1% = a burn rate of 14.4. The budget lasts 30 days ÷ 14.4 ≈ 2.1 days ≈ 50 hours. That is why 14.4× is the classic paging threshold: one hour of it spends 2% of the month's budget.

Numbers: Numbers to know.

Review this in your daily deck → All cards in Observability