Attendance Rate Calculator Formula

Understand the math behind the attendance rate calculator. Each variable explained with a worked example.

Formulas Used

Attendance Rate

attendance_rate = days_present / total_school_days * 100

Total Absences

total_absences = total_school_days - days_present

Unexcused Absences

unexcused_absences = max(unexcused, 0)

Chronically Absent (below 90%)?

chronic_absence_flag = days_present / total_school_days * 100 < 90 ? 1 : 0

Variables

VariableDescriptionDefault
total_school_daysTotal School Days90
days_presentDays Present82
excused_absencesExcused Absences5
unexcusedDerived value= total_school_days - days_present - excused_absencescalculated

How It Works

How Attendance Rate is Calculated

Attendance rate measures the proportion of scheduled days a student was present.

Formula

Attendance Rate = Days Present / Total School Days x 100

Chronic Absenteeism

A student is considered chronically absent when their attendance drops below 90%, meaning they miss 10% or more of school days. Research consistently shows chronic absenteeism is one of the strongest predictors of academic failure.

Worked Example

90 school days, student was present for 82, with 5 excused absences.

total_school_days = 90days_present = 82excused_absences = 5
  1. 01Attendance rate: 82 / 90 x 100 = 91.1%
  2. 02Total absences: 90 - 82 = 8
  3. 03Unexcused: 8 - 5 = 3
  4. 04Below 90%? No (91.1% >= 90%)

Ready to run the numbers?

Open Attendance Rate Calculator