Thornwell Charter School

Thornwell Charter School is a K-12 alternative public charter school in Clinton, SC, serving 525 students under the Charter Institute at Erskine, with a very low student-teacher ratio of 11.7:1 and a student body where 100% qualify for free or reduced lunch.

The most striking finding is the school's "late bloomer" academic profile. In 3rd and 4th grade, proficiency rates in ELA and math often fall below district and state averages—for example, only 18% of 4th graders were proficient in math in 2025-2026, compared to 34.8% for the district. However, starting in 6th grade, students catch up and frequently surpass district averages. By 6th grade, math proficiency reached 47.7% versus the district's 32.3%, and 8th-grade ELA hit 60.5%. This growth culminates in exceptional high school outcomes: the graduation rate is 93.1% (compared to 82.8% for the district and 86.7% for the state), and the dropout rate is 0.0%. Students also shine on End-of-Course exams, with English 2 proficiency at 88.1% and Algebra 1 at 66.7%, both well above district averages.

The school's biggest challenge is chronic absenteeism, which has climbed to 22.9%—double the district average of 11.5% and roughly in line with the state. This is a concern, especially given the high-poverty population the school serves. Yet the data tells a powerful story: students who attend regularly appear to make remarkable progress, entering behind their peers and leaving ahead. The school has also increased per-student spending from $10,597 to $12,988, investing in the small class sizes and individualized attention that likely drive these gains. For parents, Thornwell offers a compelling option if you're looking for a school that prioritizes student retention, builds strong high school readiness, and demonstrates a clear ability to accelerate learning over time—even if early elementary scores may initially look lower than surrounding schools.