The Diversity Index is a scale of 0 to 100 that represents the likelyhood that two persons, chosen at random from the same area, belong to different race or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
| County | Diversity Index | |
|---|---|---|
| 1. | Garrett County | 8.5 |
| 2. | Carroll County | 24.7 |
| 3. | Allegany County | 25.7 |
| 4. | Queen Anne's County | 29.5 |
| 5. | Cecil County | 31.6 |
| 6. | Worcester County | 36.9 |
| 7. | Calvert County | 40.2 |
| 8. | Kent County | 40.8 |
| 9. | Washington County | 42.0 |
| 10. | Talbot County | 43.3 |
| 11. | Harford County | 44.3 |
| 12. | St. Mary's County | 46.3 |
| 13. | Caroline County | 48.2 |
| 14. | Frederick County | 52.2 |
| 15. | Anne Arundel County | 55.8 |
| 16. | Dorchester County | 56.7 |
| 17. | Wicomico County | 57.3 |
| 18. | Baltimore city | 57.8 |
| 19. | Somerset County | 58.2 |
| 20. | Baltimore County | 62.2 |
