SLO Target Calculator

Work out slo target instantly with clear inputs, formula shown and shareable results.

About SLO Target Calculator

An error budget is simply (1 - SLO) multiplied by the period, expressed either as time or as failed requests. 99.9 percent over 30 days is 43.2 minutes or 0.1 percent of requests. Its purpose is to make reliability a shared decision: while budget remains, shipping is allowed; when it is exhausted, reliability work takes priority automatically rather than by argument.

Formula

Error budget

budget = (1 - SLO) x period; in minutes = (1 - SLO) x days x 1440; in requests = (1 - SLO) x requests per day x days

Worked example

With the default values below, SLO Target Calculator returns Error budget for the period of 43.2. Change any input above and every figure here is recalculated in your browser.

Inputs used

SLO targetaccepts 50–100 %: 99.9 %
Compliance periodminimum 1 days: 30 days
Requests per dayminimum 1: 20,000,000
Error budget already consumedaccepts 0–200 %: 40 %

Results

Error budget for the period: 43.2 min
Error budget in failed requests: 600,000
Budget remaining: 25.9 min
Budget policy status: Budget healthy - continue shipping

Step by step

1Values used
2Error budget
3Error budget for the period= 43.2 min
4Error budget in failed requests= 600,000
5Budget remaining= 25.9 min
6Budget policy status= Budget healthy - continue shipping

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Should the SLO be 100 percent?

No. A perfect target leaves no budget for change, so every deployment becomes a violation. The SLO should sit just above what users actually need.

What is a burn rate?

The multiple of budget consumption relative to spending it evenly across the period. A burn rate of 14.4 exhausts a 30-day budget in about two days, which is a standard fast-burn alert threshold.