What Is an Error Budget Burn Rate Calculator?

Site reliability engineering gives each service an error budget — the downtime its SLO permits in a month. Burn rate tells you how fast that budget is being consumed relative to the calendar, and whether you're on pace to exhaust it before the month ends. It's the standard signal for deciding when to freeze releases.

How It Works

A 99.9% SLO over a 30-day month allows 43.2 minutes of downtime. After 20 days, the prorated allowance is 43.2 × (20/30) = 28.8 minutes. Burn rate divides your actual downtime by that allowance — 10 minutes gives 0.35x (healthy), 60 minutes gives 2.08x (alert). Exhaustion day projects when the budget runs out at the current rate.

Understanding Your Results

The headline number is your burn rate — 1.0x is on pace, above 1.5x is at risk, 100% used is exhausted. The three-stat bar shows the monthly budget, the share used, and the projected exhaustion day. When the rate climbs, slow releases and treat remaining budget as scarce: every incident now compounds the risk of missing the SLO entirely.