How to calculate attendance percentage
Attendance percentage is sessions attended divided by sessions held. How to calculate it, and how many more absences you can have before dropping below a required level.
Attendance % = sessions attended ÷ sessions held × 100. 172 days out of 180 is 95.6%. To find how many more sessions you can miss, multiply the total sessions by the required percentage, subtract from the total, and subtract the absences you already have.
On this page
attendance % = sessions attended ÷ sessions held × 100
A student attended 172 of 180 school days. 172 ÷ 180 = 0.9556, so attendance is 95.6%.
Try it: 172 days out of 180
Open in calculatorHow many more can I miss?
Many schools and courses require a minimum attendance, often somewhere between 75% and 90%. To find your remaining allowance:
- Multiply the total number of sessions by the required percentage. That’s the minimum you must attend.
- Subtract that from the total to get the maximum absences allowed.
- Subtract the absences you already have.
Example: a 90% requirement over 180 days. Minimum attendance: 0.9 × 180 = 162 days. Maximum absences: 180 − 162 = 18. With 8 absences so far, you can miss 10 more.
Try it: 90% of 180 days
Open in calculatorMid-term check
A university course has 40 sessions and requires 75% attendance. So far 32 sessions have happened, and you’ve attended 26.
- Current attendance: 26 ÷ 32 = 81.25%
- Minimum for the course: 0.75 × 40 = 30 sessions
- Maximum absences: 40 − 30 = 10
- Absences so far: 32 − 26 = 6
- Remaining allowance: 10 − 6 = 4 sessions
Your current percentage looks comfortable, but the full-course number is what counts.
Rounding near the line
If the requirement is 75% and the minimum works out to a fraction, round up. 75% of 30 sessions is 22.5, so you need 23 to be safe. Some institutions round in the student’s favor, but don’t count on it.
Recovering attendance
If attendance has slipped below the requirement, find how many consecutive sessions you’d need to attend to get back above it. With 20 attended out of 28 (71.4%) and a 75% target, attending the next n sessions gives (20 + n) ÷ (28 + n). That reaches 75% when 20 + n ≥ 0.75 × (28 + n), so n ≥ 4. After 4 more sessions in a row, attendance is 24 ÷ 32 = 75%.
Attendance in a workplace
The same calculation works for work attendance, training hours or meeting participation. For tracking progress toward a target more generally, see goal progress percentage and project completion percentage. For response rates in surveys, which use the same part-over-total idea, see survey response rate.
Questions
Do late arrivals count as absences?
It depends on the school or course. Some count a set number of late arrivals as one absence; others record partial attendance. Check the attendance policy.
Are excused absences included?
Policies differ. Some attendance requirements count all absences, and some exclude excused ones. Calculate it both ways if you’re unsure.
The calculator links in this guide are checked against the PercentSwift calculator every time the site is built. How we calculate explains the rounding rules. If you spot a mistake, email hello@percentswift.com.
