| Index | Onset | Massachusetts | National |
| Average Test Scores | n/a | 52% | 48% |
| Student/Teacher ratio | 13:1 | 14:1 | 16:1 |
| Total public schools | 1 | 1,167 | 79,221 |
| Total private schools | n/a | 508 | 24,874 |
| Total post-secondary schools | n/a | 193 | 7,963 |

| Index | Onset | Massachusetts | National |
| Completed 8th grade | 96.9% | 88.3% | 84.3% |
| Completed high school | 87.0% | 87.2% | 83.0% |
| Completed some college | 54.4% | 65.0% | 59.4% |
| Completed associate degree | 29.3% | 49.0% | 38.5% |
| Completed bachelors | 8.8% | 41.2% | 30.3% |
| Completed masters | 1.5% | 18.2% | 11.5% |
| Completed professional degree | 1.5% | 5.4% | 3.3% |
| Completed doctorate | 1.5% | 2.6% | 1.3% |
There are a total of 1 public schools, n/a private schools and n/a post-secondary schools in Onset. Using the proficiency score averages, the average test scores for Onset, MA schools is n/a. The average student to teacher ratio is 13:1. In Onset, MA, an average of 96.9% of students have completed 8th grade and an average of 87.0% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Mattapoisett Center, MA | 3,275 | 73% | 52.6% |
| North Falmouth, MA | 2,628 | 72% | 50.0% |
| Marion Center, MA | 1,103 | 61% | 27.1% |
| Falmouth, MA | 3,870 | 61% | 26.6% |
| East Sandwich, MA | 3,760 | 60% | 25.0% |
| Onset, MA | 1,074 | n/a |
| City | Population | Avg. Test Scores | National Avg. |
| Ore City, TX | 1,074 | 45% | 6.9% |
| Deerfield, MI | 1,074 | 40% | 17.7% |
| Aspen Park, CO | 1,075 | 50% | 4.7% |
| Mineral Springs, AR | 1,075 | 25% | 49.0% |
| Randolph, NY | 1,073 | 46% | 4.5% |
| Onset, MA | 1,074 | n/a |