SLO Error Budget Calculator — Free Online Tool

Calculate SLO availability, allowed downtime, allowed errors, remaining error budget, budget consumption, and burn rate offline for SRE planning.

Use this free online SLO Error Budget Calculator directly in your browser. No signup required, no data leaves your device. Part of Utilier — a collection of 133+ developer utilities.

What is SLO Error Budget Calculator?

SLO Error Budget Calculator helps SRE, DevOps, and platform teams reason about reliability targets. Enter a target percentage, time window, total events, bad events, and elapsed time to estimate budget consumption and burn rate.

  • Availability: Compute observed availability from good and bad request counts.
  • Error budget: Calculate allowed errors, remaining errors, and consumed budget percentage.
  • Burn rate: Estimate whether the current failure rate is consuming budget faster than expected.

Why use slo calculator?

Reliability planning is easier when teams can quickly translate SLO targets into concrete downtime and error budgets.

  • Offline: No monitoring backend or production data connection is required.
  • Planning friendly: Use for launch readiness, incident review, and reliability tradeoff discussions.
  • Fast scenarios: Change targets, window length, traffic, and errors to compare outcomes.

When to use slo calculator

Use when designing, reviewing, or operating SLOs.

  • Estimating allowed downtime for a monthly or quarterly SLO.
  • Checking whether an incident exhausted error budget.
  • Explaining burn rate and budget consumption during reviews.

How to use slo calculator

Enter SLO inputs and review calculated budget values.

  1. Enter target: Set the SLO target percentage and rolling window length.
  2. Enter events: Provide total request/event count and bad request/error count.
  3. Review burn: Use budget consumed and burn rate to decide whether action is needed.

Key features

  • Allowed downtime: Shows how much downtime a target allows over the selected window.
  • Request budget: Converts request volume and target into allowed bad events.
  • Status signal: Labels healthy, fast-burning, and exhausted budget states.

Privacy and availability

  • Runs entirely in your browser — zero server processing
  • No signup or account required
  • Works offline once loaded
  • Fast, lightweight, no external dependencies
  • Available as a browser extension for Chrome and Firefox