# Change Failure Rate Calculator

> Work out the share of production changes that caused a failure.

Page: https://freecalculator.tech/tools/change-failure-rate-calculator
Last reviewed: 2026-09-16

## Formula

Change failure rate = Failed changes / Changes released to production

- Change failure rate = Failed changes / Changes released to production.
- Inputs used: Changes released to production, Changes that caused a failure.
- Edge handling: Changes released to production is required.; Changes released to production cannot be negative.; Changes released to production must be no more than 1000000000000.; Changes that caused a failure is required.; Changes that caused a failure cannot be negative..

## Inputs

- Changes released to production
- Changes that caused a failure

## Worked example: 7 failures out of 86 changes

The measured rate for your period; no acceptable rate is implied.
1. Start with Changes released to production: 86, Changes that caused a failure: 7.
2. Apply the method: Change failure rate = Failed changes / Changes released to production.
3. The measured rate for your period; no acceptable rate is implied.

## Common questions

### Where does this formula come from?

Deployment frequency is deployments to production divided by the length of the period; change failure rate is the share of changes to production that cause degraded service requiring remediation; failed deployment recovery time is the time taken to restore service after such a change. See the source link on this page.

### What kind of calculation is this?

The share of production changes that led to degraded service needing remediation. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

### What are its limits?

Arithmetic over the figures entered — it cannot tell whether the underlying monitoring, incident records or change records are complete. A mean over a short period, or over few events, is a weak description of behaviour. Sensitive to how a failure is defined; two teams with different definitions cannot be compared.

### How do I use the Change Failure Rate Calculator?

Enter the required values for Changes released to production, Changes that caused a failure. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.

### What formula does the Change Failure Rate Calculator use?

Change failure rate = Failed changes / Changes released to production The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.

### Can the Change Failure Rate Calculator be used for exact decisions?

Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.

## Limitations and assumptions

- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this change failure rate calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.

## Sources

- DevOps Research and Assessment, Google Cloud — https://dora.dev/guides/dora-metrics-four-keys/

## Cite this page

- APA: Free Calculator. (2026, September 16). Change Failure Rate Calculator. https://freecalculator.tech/tools/change-failure-rate-calculator
- MLA: "Change Failure Rate Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/change-failure-rate-calculator.
- Link: Change Failure Rate Calculator — Free Calculator, https://freecalculator.tech/tools/change-failure-rate-calculator