SLA Uptime and Error Budget Calculator

Pick a calculation, enter your target and period, and read the downtime or error budget.

Setup

Track budget consumption from SLO target, incident, or burn rate

Choose an analysis mode

Start from a target, a real incident, or a current burn check. The tool turns each one into budget consumed, budget remaining, and whether the current pace is sustainable.

Target to budget Incident to budget remaining Burn rate check Request error budget

Window

Fixed reporting windows: 28 or 30 days as selected; quarter = 91.3125 days; year = 365.25 days. These are duration estimates, not calendar months.

SLO target (%)

Common SLO presets

Use this when you only know the SLO target and need the allowed downtime budget before any incidents are applied.

Expected requests in window

Requests processed so far

Failed requests so far

The request budget counts failed requests. The pace estimate assumes future requests fail at the same rate as those processed so far.

Advanced incident and burn inputs

Consumed downtime

Downtime unit

Elapsed time in window

Elapsed unit

Incident mode shows how much budget was spent and what remains. Burn mode adds pace, exhaustion risk, and whether the current trend can survive the rest of the window.

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Reliability Workflow

Allowed downtime and target comparison Budget remaining and burn rate Incident timeline math

Calculate consumed and remaining error budget with burn-rate diagnostics for operational decision support.

Interpretation

Run a scenario to turn SLO targets and outage time into budget remaining, burn rate, and an operational decision hint.

Outputs

Formula

After calculation, this panel shows the active budget or burn-rate formula used for the current mode.

Budget diagnostics appear here with used budget, remaining budget, burn rate, and an at-a-glance operating status.

Standard window breakdown

Calculate a scenario to compare how the same target or incident behaves across day, week, 28-day, 30-day, quarter, and year windows.

Uptime, downtime and error budgets

An uptime target such as 99.9% allows a fixed amount of downtime per month or year. An SLO error budget is the same idea applied to your own objective: subtract incident time to see how much budget is left and how fast you are burning it.

Some people, when confronted with a problem, think ‘I know, I’ll use regular expressions.’ Now they have two problems.
Jamie Zawinski