SLA / Error Budget Calculator

An error budget is the inverse of your SLA target. If your SLA promises 99.9% uptime, your error budget is 0.1% of the total time in the measurement period. This budget represents the maximum amount of downtime or errors your service can experience while still meeting the SLA commitment. SRE teams use error budgets as a shared currency between reliability and feature velocity -- as long as budget remains, teams can ship fast.

The burn rate measures how quickly you are consuming your error budget relative to the ideal rate. A burn rate of 1.0x means you will exactly exhaust your budget by the end of the SLO period. A burn rate of 2.0x means you are consuming budget twice as fast, and will exhaust it halfway through the period. Google SRE practices recommend multi-window burn rate alerts (e.g., 14.4x over 1 hour, 6x over 6 hours) to catch both acute incidents and slow degradation.

When the error budget is fully consumed, many organizations implement an error budget policy. This typically means freezing feature deployments and redirecting engineering effort toward reliability improvements until the budget recovers. The policy creates a natural feedback loop: if a team ships a buggy release that burns through the error budget, they must invest in reliability before shipping more features.