| Index | Garretts Mill | Maryland | National |
| Average Test Scores | n/a | 40% | 48% |
| Student/Teacher ratio | n/a | 16:1 | 16:1 |
| Total public schools | n/a | 1,163 | 79,221 |
| Total private schools | n/a | 674 | 24,874 |
| Total post-secondary schools | n/a | 112 | 7,963 |

| Index | Garretts Mill | Maryland | National |
| Completed 8th grade | 78.5% | 87.5% | 84.3% |
| Completed high school | 78.5% | 86.5% | 83.0% |
| Completed some college | 42.6% | 64.2% | 59.4% |
| Completed associate degree | 21.9% | 44.8% | 38.5% |
| Completed bachelors | 21.9% | 38.4% | 30.3% |
| Completed masters | 6.7% | 17.7% | 11.5% |
| Completed professional degree | 0.0% | 5.5% | 3.3% |
| Completed doctorate | 0.0% | 2.5% | 1.3% |
There are a total of n/a public schools, n/a private schools and n/a post-secondary schools in Garretts Mill. Using the proficiency score averages, the average test scores for Garretts Mill, MD schools is n/a. The average student to teacher ratio is n/a. In Garretts Mill, MD, an average of 78.5% of students have completed 8th grade and an average of 78.5% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Purcellville, VA | 10,402 | 89% | 84.8% |
| Lovettsville, VA | 2,511 | 87% | 80.2% |
| Poolesville, MD | 5,340 | 70% | 45.8% |
| Middletown, MD | 4,813 | 69% | 44.4% |
| Boonsboro, MD | 3,716 | 60% | 25.5% |
| Garretts Mill, MD | 359 | n/a |
| City | Population | Avg. Test Scores | National Avg. |
| Anamoose, ND | 359 | 45% | 6.3% |
| Trinidad, CA | 359 | 51% | 6.3% |
| Bode, IA | 359 | 60% | 25.0% |
| Searchlight, NV | 359 | 50% | 4.2% |
| Grand View, ID | 359 | 30% | 37.5% |
| Garretts Mill, MD | 359 | n/a |