Is student-teacher ratio the same as class size?

Not exactly. Ratio counts all teachers (including specialists and support), while class size is the actual number in a classroom.

What ratio do private schools typically have?

Private schools average about 12:1, compared to the public school average of 16:1.

How does the ratio affect learning?

Research shows significant benefits below 20:1, especially for younger students. The Tennessee STAR study found lasting benefits at 13-17 students per class.

Student-Teacher Ratio Calculator

Calculate the student-to-teacher ratio for a school or district and compare it to recommended benchmarks.

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Total Students Enrolled

Full-Time Equivalent Teachers

Student-Teacher Ratio

18.0

Approx Students per Class18

Teachers for 15:1 Ratio30

Teacher Shortage/Surplus-5

Student-Teacher Ratio vs Total Students Enrolled

View formula & how it works →

Understanding Student-Teacher Ratio

The student-teacher ratio divides total enrollment by the number of full-time equivalent (FTE) teachers.

Formula

Ratio = Total Students / FTE Teachers

Benchmarks

Elementary: 15:1 or lower is ideal

Secondary: 18:1 or lower

National average (U.S.): approximately 16:1

Lower ratios generally correlate with better student outcomes, especially in early grades and for at-risk populations.

Example Calculation

A school has 450 students and 25 FTE teachers.

01Ratio: 450 / 25 = 18.0:1
02For 15:1 ratio: ceil(450 / 15) = 30 teachers needed
03Teacher gap: 25 - 30 = -5 (shortage of 5)

Student-Teacher Ratio Calculator

Understanding Student-Teacher Ratio

Formula

Benchmarks

Example Calculation

Frequently Asked Questions

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