Student-Teacher Ratio Calculator
Enter total student and teacher counts to calculate the student-teacher ratio, commonly used when comparing schools, programs, or classroom sizes.
Student-teacher ratio
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Enter headcounts to calculate.
How the Student-Teacher Ratio formula works
A simplified ratio, expressed relative to one teacher:
Ratio = Total students / Total teachers
Step-by-step calculation
- Divide the total number of students by the total number of teachers.
- Express the result as a ratio relative to a single teacher, such as 18:1.
Worked example
A school with 450 students and 25 teachers: Ratio = 450/25 = 18, expressed as an 18:1 student-teacher ratio.
Frequently asked questions
Does a lower ratio always mean smaller class sizes?
Not necessarily — student-teacher ratio is a school- or district-wide average and can be affected by specialists, support staff, and part-time teachers included in the count, so it doesn't always match the actual number of students in a typical classroom.