What does the selection-rate and impact-ratio calculator produce?
Calculate two selection rates, their percentage-point difference and the comparison-to-reference impact ratio using customer-entered counts and threshold.
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.
- Reference group applicants or cases (required). Enter the complete reference group count for the same process and period.
- Reference group selected (required). Enter favorable outcomes for the reference group.
- Comparison group applicants or cases (required). Enter the complete comparison group count for the same process and period.
- Comparison group selected (required). Enter favorable outcomes for the comparison group.
- Review threshold percentage (required). Enter the organization’s review threshold. A common 80 percent screen is only a rule of thumb and is not a legal conclusion.
| Field | What to enter | Fictional example |
|---|---|---|
| Reference group applicants or casesRequired | Enter the complete reference group count for the same process and period.Accepted range 0 to 1000000000. | 600 |
| Reference group selectedRequired | Enter favorable outcomes for the reference group.Accepted range 0 to 1000000000. | 240 |
| Comparison group applicants or casesRequired | Enter the complete comparison group count for the same process and period.Accepted range 0 to 1000000000. | 400 |
| Comparison group selectedRequired | Enter favorable outcomes for the comparison group.Accepted range 0 to 1000000000. | 128 |
| Review threshold percentageRequired | Enter the organization’s review threshold. A common 80 percent screen is only a rule of thumb and is not a legal conclusion.Accepted range 0 to 100. | 80 |
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 selection-rate and impact-ratio 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.
- Common fairness metricsSelection and error-rate definitions, and the need to interpret metrics in context. Demographic parity, equalized odds and limits of the four-fifths screen.Fairlearn project. Reviewed 2026-10-07.
- Binary confusion matrix definitionsTrue positive, false positive, false negative and true negative count definitions. Binary classification confusion matrix.scikit-learn project. Reviewed 2026-10-07.
Common questions
What information does the selection-rate and impact-ratio calculator need?
Enter reference group applicants or cases (required). Enter the complete reference group count for the same process and period; reference group selected (required). Enter favorable outcomes for the reference group; comparison group applicants or cases (required). Enter the complete comparison group count for the same process and period; comparison group selected (required). Enter favorable outcomes for the comparison group; review threshold percentage (required). Enter the organization’s review threshold. A common 80 percent screen is only a rule of thumb and is not a legal conclusion. Freeze the complete population, process, period and approved outcome criteria before entering aggregate counts.
What does the selection-rate and impact-ratio calculator produce?
Selection rate for each entered group. Comparison-to-reference impact ratio. Percentage-point difference and comparison against the entered review threshold. 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 output is a descriptive screen. It does not establish adverse impact, discrimination, statistical significance or a legal violation.
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 selection-rate and impact-ratio calculator for this task?
Produce transparent calculations from your populations. The output is a descriptive screen. It does not establish adverse impact, discrimination, statistical significance or a legal violation.
What still needs review?
The output is a descriptive screen. It does not establish adverse impact, discrimination, statistical significance or a legal violation.
Aggregate counts do not establish complete evidence, comparable samples or valid labels. No individual-record audit, model test or release approval is performed.
Rates and entered gates describe the supplied counts. They do not establish statistical significance or a legal conclusion.