Helm Release History Calculator
Calculate storage and lookup overhead from retaining many Helm release history entries.
About Helm Release History Calculator
Both deploys (installs/upgrades) and rollbacks create a new revision in a Helm release's history, so the total number of history entries ever created is the sum of the two. Helm continuously prunes the oldest entries once the count exceeds `--history-max`, so the number actually retained and available for future rollback is capped at that limit — meaning very active releases can lose the ability to roll back to early revisions long before the release itself is decommissioned.
Formula
retainedEntries = min(deploys + rollbacks, maxHistory)
- D
- Number of deploy operations (installs + upgrades)
- B
- Number of rollback operations
- H
- Max history setting (0 = unlimited)
- R
- Retained history entries
Worked example
With the default values below, Helm Release History Calculator returns Retained History Entries of 10. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Deploys (Installs + Upgrades)accepts 0–1,000,000 entries
- 18 entries
- Rollbacksaccepts 0–1,000,000 entries
- 3 entries
- Max History (--history-max)accepts 0–1,000 revisions
- 10 revisions
Results
- Retained History Entries
- 10 revisions
- Total History Entries Created
- 21 revisions
- Pruned Entries
- 11 revisions
Step by step
- 1History entries = deploys + rollbacks= 21 entries
- 2Retained after pruning= 10 entries
- 3Pruned entries= 11 entries (52.4%)
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 whole numbers, 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
Does a rollback count as a deploy for history purposes?
No — Helm tracks rollbacks as their own revision type distinct from install/upgrade, but both consume a slot in the same bounded history list subject to `--history-max` pruning.
Can I recover a pruned revision?
Not from Helm's own storage — once pruned, the Secret/ConfigMap backing that revision is deleted; recovery would require an external backup of release manifests (e.g. keeping rendered YAML in Git) taken before pruning occurred.
Should history-max be higher for releases that roll back often?
Yes — if a release frequently needs to roll back several versions, a higher `--history-max` keeps more rollback targets available; balance this against the added Secret storage each retained revision costs.