Concurrent Build Calculator

Calculate the maximum number of builds that can run concurrently given resources.

About Concurrent Build Calculator

The maximum number of builds Jenkins can run at any single instant is bounded strictly by the total executor count across all connected, online agents — one executor runs exactly one build at a time. When the number of simultaneously requested builds exceeds available executors, the excess forms a queue rather than running immediately, waiting for an executor to free up; this is the same constraint that drives wait time in the build queue calculator.

Formula

queuedBuilds = max(0, requestedBuilds - executors)

B: Requested concurrent builds
E: Total available executors
Q: Builds that will queue

Worked example

With the default values below, Concurrent Build Calculator returns Max Concurrent Builds of 8. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total Executorsaccepts 1–100,000 executors: 8 executors
Requested Concurrent Buildsaccepts 0–1,000,000 builds: 13 builds

Results

Max Concurrent Builds: 8 builds
Builds That Will Queue: 5 builds
Executor Utilization: 100.0%

Step by step

1Max concurrent = executors= 8 builds
2Running now = min(executors, requested)= 8 builds
3Queued = max(0, requested − executors)= 5 builds

Assumptions and limits

The result is derived only from the 2 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 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

Can a single build ever use more than one executor?

Not by default for a single job's main flow, but a declarative pipeline with a `parallel {}` block launching multiple `agent` directives effectively consumes one executor per concurrent branch, so a single pipeline run can occupy several executors at once.

Do executor labels affect this calculation?

Yes in practice — this calculator assumes all executors are fungible and available to every requested build; if builds require specific labels (e.g. `docker`, `gpu`), the effective competing pool is only the executors matching that label, not the cluster-wide total.

What happens to queued builds if none ever get an executor?

They remain queued indefinitely (subject to any configured queue timeout) until an executor becomes free or the job is manually cancelled; persistent queuing under peak load is a strong signal to add executors or improve throttling.