What does the evaluation confidence interval calculator produce?
Calculate a 95 percent Wilson score interval for an observed evaluation success rate and compare its lower bound and width with customer-entered review thresholds.
The working area above saves numeric inputs in this browser and exposes every formula. It does not decide fairness, safety, compliance or release approval.
What do you need before you start?
- Freeze the complete population, process, period and approved outcome criteria before entering aggregate counts.
- Use ordinary nonnegative decimal notation. Counts must be whole numbers through one billion. Review thresholds support increments of 0.1 percentage points.
- Confirm comparable populations and source labels. The tool does not collect individual records or test an AI model.
What information do you enter?
The browser calculator accepts only the aggregate numeric inputs listed below.
- Evaluation observations (required). Enter the complete number of independent observations in the evaluation sample.
- Successful observations (required). Enter observations that met the same approved success criterion.
- Target success rate percentage (required). Enter the organization’s target rate for this evaluation. The tool does not supply a target.
- Minimum acceptable lower bound percentage (required). Enter the lowest 95 percent interval bound the organization will accept for review.
- Maximum interval width in percentage points (required). Enter the widest 95 percent interval the organization will accept for review.
| Field | What to enter | Fictional example |
|---|---|---|
| Evaluation observationsRequired | Enter the complete number of independent observations in the evaluation sample.Accepted range 0 to 1000000000. | 400 |
| Successful observationsRequired | Enter observations that met the same approved success criterion.Accepted range 0 to 1000000000. | 356 |
| Target success rate percentageRequired | Enter the organization’s target rate for this evaluation. The tool does not supply a target.Accepted range 0 to 100. | 90 |
| Minimum acceptable lower bound percentageRequired | Enter the lowest 95 percent interval bound the organization will accept for review.Accepted range 0 to 100. | 85 |
| Maximum interval width in percentage pointsRequired | Enter the widest 95 percent interval the organization will accept for review.Accepted range 0 to 100. | 7 |
What you can download
Every result must identify its supplied facts, assumptions and unresolved items.
| Free result | Included downloads |
|---|---|
Enter your information, inspect the on-screen result and keep a browser backup. Editing and direct copies of your entered information stay free. |
These supported outputs are free. No checkout is required. |
How does the evaluation confidence interval calculator work?
- 1Freeze the evidence basis
Retain the source population, evaluation version, success criterion and review thresholds in your own controlled records.
- 2Enter the bounded counts
Use the numeric fields above or a clearly fictional example. Correct counts that exceed their population or imply an impossible confusion matrix.
- 3Calculate and inspect
Review every descriptive rate and entered gate. Gates use exact count and decimal expressions. Displayed percentages round to two decimal places.
- 4Keep a restorable backup
Download the free backup before clearing or replacing work. Earlier JSON result downloads can restore inputs. Restoring recalculates results and preserves previous browser inputs.
- 5Prepare the finalized calculation
Download all seven finalized files free. Browser preparation does not transfer inputs to a provider.
Method and sources
Apply the steps above to the supported inputs. Use the listed source sections to review the rule basis, assumptions and limits.
- Confidence intervals for a binomial proportionThe Wilson score interval formula and the distinction from exact binomial intervals. 7.2.4.1 Confidence intervals.National Institute of Standards and Technology. Reviewed 2026-10-07.
- Binomial proportion observations and samplingBinary observations and sampling assumptions underlying proportion methods. 7.2.4 Proportion of defectives.National Institute of Standards and Technology. Reviewed 2026-10-07.
Common questions
What information does the evaluation confidence interval calculator need?
Enter evaluation observations (required). Enter the complete number of independent observations in the evaluation sample; successful observations (required). Enter observations that met the same approved success criterion; target success rate percentage (required). Enter the organization’s target rate for this evaluation. The tool does not supply a target; minimum acceptable lower bound percentage (required). Enter the lowest 95 percent interval bound the organization will accept for review; maximum interval width in percentage points (required). Enter the widest 95 percent interval the organization will accept for review. Freeze the complete population, process, period and approved outcome criteria before entering aggregate counts.
What does the evaluation confidence interval calculator produce?
Observed success rate and difference from the entered target. 95 percent Wilson score confidence interval. Comparison with entered lower-bound and interval-width thresholds. Free restorable browser backup and complete JSON calculation record. Seven-file finalized export. Formal PDF, editable DOCX, Excel, results CSV, complete input and result JSON, file hashes and instructions. Review unresolved findings and limitations before use.
Who makes the final decision?
A responsible person reviews the result. The calculation assumes a binomial outcome and independent observations. Sampling design, representativeness and release authority require qualified human review.
Is this tool free?
Yes. The on-screen result and listed downloads are free. No checkout is required. Keep local backups and review the stated method and limits.
Can I use the evaluation confidence interval calculator for this task?
Calculate a 95 percent Wilson score interval for observed success rates. The calculation assumes a binomial outcome and independent observations. Sampling design, representativeness and release authority require qualified human review.
What still needs review?
The calculation assumes a binomial outcome and independent observations. Sampling design, representativeness and release authority require qualified human review.
Aggregate counts do not establish complete evidence, comparable samples or valid labels. No individual-record audit, model test or release approval is performed.
The two-sided nominal 95 percent Wilson interval uses z = 1.96. It assumes independent binomial observations, is not an exact binomial interval and does not correct for clustering or multiple comparisons.