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 * 100Total Absences
total_absences = total_school_days - days_presentUnexcused Absences
unexcused_absences = max(unexcused, 0)Chronically Absent (below 90%)?
chronic_absence_flag = days_present / total_school_days * 100 < 90 ? 1 : 0Variables
| Variable | Description | Default |
|---|---|---|
total_school_days | Total School Days | 90 |
days_present | Days Present | 82 |
excused_absences | Excused Absences | 5 |
unexcused | Derived value= total_school_days - days_present - excused_absences | calculated |
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.
- 01Attendance rate: 82 / 90 x 100 = 91.1%
- 02Total absences: 90 - 82 = 8
- 03Unexcused: 8 - 5 = 3
- 04Below 90%? No (91.1% >= 90%)
Frequently Asked Questions
What counts as an excused absence?
Policies vary, but typically illness with a doctor note, family emergencies, and religious observances are excused.
What is chronic absenteeism?
Missing 10% or more of school days (below 90% attendance), regardless of whether absences are excused or not.
How does attendance affect grades?
Students who miss more than 10% of classes typically score 20-30% lower on assessments, according to educational research.
Ready to run the numbers?
Open Attendance Rate Calculator