Attendance percentage
Attendance % = classes attended ÷ classes held × 100. Attending 45 of 60 classes: 45 ÷ 60 × 100 = 75%.
Which rule applies to you?
The minimum attendance — 75% or another figure — and any relaxation is set by your own college, university or board. Read its ordinance or notice; this guide only does the arithmetic.
Classes you must attend to reach 75%
If you attend every class from now on, you need x = (0.75 × held − attended) ÷ 0.25 more classes, rounded up. For 75% that is the same as 3 × held − 4 × attended.
Example: 45 attended out of 70 held = 64.3%. x = 3 × 70 − 4 × 45 = 210 − 180 = 30 classes. Check: 75 ÷ 100 = 75%.
Classes you can miss and stay at 75%
If you are above 75%, you can miss y = (attended − 0.75 × held) ÷ 0.75 classes in a row, rounded down.
Example: 60 attended out of 72 held = 83.3%. y = (60 − 54) ÷ 0.75 = 8 classes. Check: 60 ÷ 80 = 75%.
Any other target
For a target p (0.80 for 80%): must attend x = (p × held − attended) ÷ (1 − p), rounded up; can miss y = (attended − p × held) ÷ p, rounded down.
| Held / attended | Now | For 75% |
|---|---|---|
| 40 / 28 | 70.0% | Attend 8 more (36 / 48) |
| 50 / 35 | 70.0% | Attend 10 more (45 / 60) |
| 80 / 64 | 80.0% | Can miss 5 (64 / 85 = 75.3%) |
| 100 / 90 | 90.0% | Can miss 20 (90 / 120) |
Labs and lectures counted separately?
Many colleges count theory and practical attendance separately. Work out each one on its own with the tool.
Questions people ask
How do I calculate my attendance percentage?
Classes attended ÷ classes held × 100. 45 of 60 is 75%.
How many classes do I need to attend to reach 75%?
Attending every class from now: 3 × classes held − 4 × classes attended (rounded up to a whole class). With 45 of 70 that is 30 more.
How many classes can I miss and still have 75%?
(attended − 0.75 × held) ÷ 0.75, rounded down. With 60 of 72 you can miss 8 in a row.
Is 75% attendance compulsory everywhere?
The minimum is set by your own college, university or board — read its rules. The calculator works for any target.