Adverse impact calculator

How to use this calculator

1. 1.Enter the total number of employees in each group who were in the selection pool — everyone considered for this RIF, selected or not.
2. 2.Enter the number of employees in each group who were selected for termination.
3. 3.The calculator applies the EEOC 4/5ths rule: if any group's selection rate is less than 80% of the highest-rate group's selection rate, adverse impact exists.
4. 4.Groups with fewer than 30 employees are flagged. The 4/5ths rule is less reliable at small sample sizes — consider Fisher's exact test.

Selection rate

The percentage of employees in a group who were selected for termination. For example, if 4 of 20 Black employees were selected, the selection rate is 20%.

Comparator group

The group with the highest selection rate. All other groups are compared against it. The comparator is not necessarily the majority group.

Ratio

The protected group's selection rate divided by the comparator's selection rate. A ratio below 0.80 triggers the 4/5ths rule and indicates adverse impact.

The 4/5ths rule

Under the EEOC Uniform Guidelines, a selection rate for any group that is less than 80% of the rate for the highest-rate group is generally considered evidence of adverse impact.

Small sample caveat

When a group has fewer than 30 employees, the 4/5ths rule is less statistically reliable. EEOC guidance and courts have accepted Fisher's exact test or standard deviation analysis for small samples. Flag these for counsel.

What to do if adverse impact is found

Do not finalize the list. Review whether the selection criteria can be adjusted while maintaining legitimate business justification. Document the analysis and any changes. Have counsel review before proceeding.

Does adverse impact analysis apply to every RIF?

Yes. There is no minimum size threshold under Title VII or the ADEA. Even a small RIF can give rise to a discrimination claim if the selection disproportionately affects a protected group. The 4/5ths rule may not be statistically meaningful for very small groups, but you should still document that you reviewed the demographic composition of the selection.

Which groups must I analyze?

At minimum: race/ethnicity (as defined by the EEOC's five categories), sex, and age (under 40 vs. 40 and older under the ADEA). If your workforce includes other protected classes that might be disproportionately affected, counsel may recommend analyzing those as well.

What is the "decisional unit" and how does it affect the analysis?

The decisional unit is the pool of employees who were considered for selection, whether selected or not. It should reflect all employees in the roles, departments, or locations where the selection criteria were applied. Defining the unit too narrowly can mask adverse impact; defining it too broadly can dilute it. Counsel should help define the appropriate unit before the analysis runs.

What if I find adverse impact?

Stop. Do not finalize the list. Work with counsel to determine whether the selection criteria can be modified while maintaining legitimate business justification. Document every step: the original criteria, the analysis results, the changes considered, and the rationale for any adjustments. If adverse impact cannot be eliminated, you may still be able to defend the selection under the business necessity doctrine, but that requires a high bar and legal review.

Is the 4/5ths rule the only test?

No. Courts and the EEOC also use standard deviation analysis and Fisher's exact test, particularly when sample sizes are small. The 4/5ths rule is the most common initial screen, but a passing result does not guarantee you are free of legal risk, and a failing result is not automatically dispositive. Treat this calculator as a first-pass screen, not a legal conclusion.

Should I run the analysis before or after finalizing the list?

Before. The purpose of the analysis is to catch and correct adverse impact before the list is locked. Running it after finalization — or not running it at all — is one of the most common and costly mistakes in RIF planning. If you adjust the list after the analysis, document the reason for every change.