| Index | Mountainside | New Jersey | National |
| Average Test Scores | 77% | 52% | 48% |
| Student/Teacher ratio | 12:1 | 13:1 | 16:1 |
| Total public schools | 3 | 1,604 | 79,221 |
| Total private schools | n/a | 823 | 24,874 |
| Total post-secondary schools | n/a | 157 | 7,963 |
| Index | Mountainside | New Jersey | National |
| Completed 8th grade | 93.4% | 87.5% | 84.3% |
| Completed high school | 93.4% | 86.3% | 83.0% |
| Completed some college | 78.6% | 60.7% | 59.4% |
| Completed associate degree | 64.9% | 43.9% | 38.5% |
| Completed bachelors | 54.8% | 37.5% | 30.3% |
| Completed masters | 24.5% | 14.4% | 11.5% |
| Completed professional degree | 9.1% | 4.0% | 3.3% |
| Completed doctorate | 2.6% | 1.5% | 1.3% |
There are a total of 3 public schools, n/a private schools and n/a post-secondary schools in Mountainside. Using the proficiency score averages, the average test scores for Mountainside, NJ schools is 77%. The average student to teacher ratio is 12:1. In Mountainside, NJ, an average of 93.4% of students have completed 8th grade and an average of 93.4% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Essex Fells, NJ | 2,112 | 85% | 76.0% |
| Short Hills, NJ | 14,190 | 83% | 73.8% |
| Mountain Lakes, NJ | 4,398 | 83% | 72.7% |
| Singac, NJ | 4,170 | 82% | 70.8% |
| Summit, NJ | 22,539 | 81% | 69.3% |
| Mountainside, NJ | 7,074 | 77% | 60.4% |
| City | Population | Avg. Test Scores | National Avg. |
| Live Oak, FL | 7,073 | 45% | 6.9% |
| Idabel, OK | 7,077 | 33% | 31.5% |
| Franklin, LA | 7,085 | 64% | 33.5% |
| Huron, OH | 7,056 | 78% | 62.5% |
| Newport, TN | 7,093 | 30% | 37.8% |
| Mountainside, NJ | 7,074 | 77% | 60.4% |
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