Attendance Calculator
Your attendance percentage, and how many classes you must attend in a row, or can still miss, to stay at the minimum.
Result…
How it's calculated
Attendance % = attended ÷ held × 100 To attend in a row: n = ⌈(min% × held − 100 × attended) ÷ (100 − min%)⌉ Can still miss: m = ⌊(100 × attended − min% × held) ÷ min%⌋
Counts every class as equal. The classes to attend assume you go to every one in a row from now; the classes you can miss assume you attend none of the next ones. Rules differ by school and country: some count labs or lectures separately, excuse medical leave, round 74.5% up, or check attendance per subject, so look up your own institution's policy before relying on a margin of one or two classes.
Your numbers, step by step
About the Attendance calculator
This attendance calculator turns the classes held and the classes you attended into an attendance percentage, then checks it against the minimum your school or university requires. If you are below the minimum, it tells you how many classes in a row you must attend to get back to it. If you are above it, it tells you how many classes you can still miss and stay at or above the line. Each answer is checked in the working, so you can see the attendance you would end up with. A 75% minimum is common at many colleges in some countries, but rules differ: some institutions count lectures and labs separately, excuse medical leave, or check each subject on its own, so read your own attendance policy. To work out other percentages, use the percentage calculator.
How to use it
- Enter the “Classes held so far”.
- Enter the “Classes attended” out of those.
- Set the “Minimum attendance required” to your institution's rule, for example 75%.
- Read your attendance, then either the classes to attend in a row or the classes you can still miss.
Worked example
60 classes held and 42 attended is 42 ÷ 60 × 100 = 70%, below a 75% minimum. You need n more in a row where (42 + n) ÷ (60 + n) is at least 75%: n = (75 × 60 − 100 × 42) ÷ 25 = 12, and 54 ÷ 72 = 75%. With 54 attended out of 60 (90%), you could miss the next 12 classes: 54 ÷ 72 is still 75%.
Updated
Questions people ask
How do I calculate my attendance percentage?
Divide the classes you attended by the classes held and multiply by 100. 28 out of 40 is 70%.
How many classes do I need to attend to reach 75%?
Use n = (75 × classes held − 100 × classes attended) ÷ 25 and round up. With 28 out of 40, that is (3,000 − 2,800) ÷ 25 = 8 classes in a row.
How many classes can I miss and stay above the minimum?
Use m = (100 × attended − minimum × held) ÷ minimum and round down. With 45 out of 50 and a 75% minimum, you can miss 10 more and be at exactly 75%.
Is 74.5% rounded up to 75%?
It depends on your institution. Some round, some do not, so the calculator never rounds up for you: plan for the exact figure.
Why can't I reach 100% attendance again?
Once you miss one class, attended is less than held, and attending more classes only brings you closer to 100% without reaching it.
Does this follow my university's attendance rules?
It counts every class the same. If your institution weights labs, excuses some absences or checks each subject separately, enter the numbers for each subject on their own and confirm the rule with your department.