Build Queue Calculator

Calculate expected wait time in a Jenkins build queue given executor availability.

About Build Queue Calculator

When more builds are queued than there are free executors, Jenkins processes them in batches roughly the size of the executor pool, so a build's expected wait time is proportional to how many 'rounds' of builds must complete ahead of it. Dividing queue length by executor count gives the number of rounds, and multiplying by average build time converts that into an estimated wall-clock wait — a simplified model that assumes builds are homogeneous and executors are fungible across them.

Formula

waitTime = (queueLength / executors) × avgBuildTime

Q: Builds currently queued
E: Available executors
t_{avg}: Average build time in minutes
W: Estimated queue wait time in minutes

Worked example

With the default values below, Build Queue Calculator returns Estimated Queue Wait Time of 18.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Builds Currently Queuedaccepts 0–100,000 builds: 12 builds
Available Executorsaccepts 1–10,000 executors: 4 executors
Average Build Timeaccepts 0.01–1,440 min: 6 min

Results

Estimated Queue Wait Time: 18.00 min
Estimated Queue Wait Time: 0.300 hr
Queue Rounds (Batches of Executors): 3.00

Step by step

1Queue rounds = queue length ÷ executors= 3.00 rounds
2Wait time = queue rounds × avg build time= 18.00 min

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, 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

Why might real wait times differ from this estimate?

Real queues have heterogeneous build durations, executor labels/restrictions that prevent some builds from using all executors, and priority/quiet-period settings — all of which this simplified average-based model doesn't capture.

What's the fastest way to reduce queue wait time?

Add more executors (more agents or higher per-agent executor count), reduce average build time itself (caching, parallelism), or use build throttling/priority plugins to ensure critical builds aren't stuck behind low-priority ones.

Does this account for builds that need a specific label?

No — it assumes any of the available executors can run the queued builds; in practice, label-restricted builds (e.g. requiring a GPU or specific OS) effectively queue against a smaller executor pool than the cluster-wide total.