Tools · Calculator
SLO burn-rate
An SLO without an error budget is a wish. This calculator turns your target and your current error rate into the three numbers that matter on call: how much budget is left, how fast it burns, and when it runs out if nothing changes.
How to read it
With a 99.9% SLO over 30 days you have 43.2 minutes of allowed unavailability. A 0.05% error rate burns the budget at ×0.5: you survive the window. At 1% errors (×10 burn), you exhaust it in 3 days — exactly the classic SRE fast-burn alert threshold (×14.4 over 1 h, ×6 over 6 h).
Assumptions and limits
- Assumes a constant error rate going forward: a projection, not a prediction.
- Treats all requests as equal; if your SLO weighs by criticality, adjust the input rate.
- The ×14.4/×6 thresholds come from the Google SRE book for 30-day windows.
The article behind it
Observability vs. monitoring · How to investigate an incident
Version 1.0 · July 2026 · Runs 100% in your browser: nothing is sent to any server.
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