| Index | Castalia | Ohio | National |
| Average Test Scores | 49% | 61% | 48% |
| Student/Teacher ratio | n/a | 17:1 | 16:1 |
| Total public schools | n/a | 3,650 | 79,221 |
| Total private schools | n/a | 1,000 | 24,874 |
| Total post-secondary schools | n/a | 393 | 7,963 |

| Index | Castalia | Ohio | National |
| Completed 8th grade | 87.7% | 86.9% | 84.3% |
| Completed high school | 85.9% | 85.6% | 83.0% |
| Completed some college | 38.5% | 55.7% | 59.4% |
| Completed associate degree | 24.6% | 35.1% | 38.5% |
| Completed bachelors | 17.6% | 26.7% | 30.3% |
| Completed masters | 4.7% | 10.0% | 11.5% |
| Completed professional degree | 0.5% | 2.7% | 3.3% |
| Completed doctorate | 0.2% | 1.1% | 1.3% |
There are a total of n/a public schools, n/a private schools and n/a post-secondary schools in Castalia. Using the proficiency score averages, the average test scores for Castalia, OH schools is 49%. The average student to teacher ratio is n/a. In Castalia, OH, an average of 87.7% of students have completed 8th grade and an average of 85.9% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Huron, OH | 7,056 | 78% | 62.5% |
| Green Springs, OH | 1,466 | 77% | 60.4% |
| Lakeside, OH | 700 | 74% | 53.8% |
| Milan, OH | 1,596 | 72% | 50.0% |
| Bellevue, OH | 8,110 | 71% | 48.3% |
| Castalia, OH | 1,186 | 49% | 1.4% |
| City | Population | Avg. Test Scores | National Avg. |
| Mound City, MO | 1,186 | 62% | 28.1% |
| Hart, TX | 1,186 | 42% | 12.5% |
| Atwood, KS | 1,186 | 35% | 28.1% |
| Kings Mills, OH | 1,187 | 83% | 73.5% |
| Bellevue, MI | 1,185 | 28% | 41.1% |
| Castalia, OH | 1,186 | 49% | 1.4% |