Attendance Calculator
Attendance percentage = classes attended ÷ classes held × 100, so 42 of 60 classes is 70%, and you need 12 classes in a row to get back to 75% (54 of 72). If you're above your target, the calculator shows how many classes you can miss instead.
By the Calculators With Steps team · Updated November 10, 2026 · How we check our math
- Classes to attend in a row to reach 75%
- 12then 54 of 72
- Compared with 75%
- 5 points below
- Classes missed
- 18of 60 held
Step-by-step working
- Attendance % = classes attended ÷ classes held × 100
- 42 ÷ 60 = 0.7
- 0.7 × 100 = 70%
- Classes to attend in a row: x = (T × t − A) ÷ (1 − t), rounded up, where t = 75% = 0.75
- x = (60 × 0.75 − 42) ÷ (1 − 0.75) = (45 − 42) ÷ 0.25 = 12
- Round up: x = 12. Check: 54 ÷ 72 × 100 = 75%
What 42 of 60 means at other targets
| Required attendance | Classes to attend in a row | Classes you can miss |
|---|---|---|
| 60% | 0 | 10 |
| 65% | 0 | 4 |
| 70% | 0 | 0 |
| 75% (yours) | 12 | 0 |
| 80% | 30 | 0 |
| 85% | 60 | 0 |
| 90% | 120 | 0 |
Rules differ: some colleges check each subject separately, some round (Anna University counts 74.5% as 75%), and some check attendance on a cut-off date before exams. This assumes every class or period counts the same.
How to use the attendance calculator
- Pick what you want to know: Attendance %, Classes to attend or Classes I can miss.
- Enter the classes you attended and the total classes held so far. The total includes the classes you missed.
- Set the required attendance. It starts at 75%, the most common minimum, but you can type 80, 85 or whatever your college uses.
- Optionally, add the classes left this term. The calculator then tells you how many of them you must attend and how many you can still miss before the term ends.
Every mode shows the working. The default view also compares your attendance with targets from 60% to 90%, which helps if different subjects or courses have different rules.
Attendance percentage formula
Attendance % = classes attended ÷ classes held × 100
Two more formulas answer the questions students ask most. Let A be the classes attended, T the classes held so far, and t the target as a decimal (75% = 0.75).
- Classes to attend in a row to reach the target: x = (T × t − A) ÷ (1 − t), rounded up.
- Classes you can miss in a row and stay at the target: y = (A − t × T) ÷ t, rounded down.
Both come from the same idea. After attending x more classes your attendance is (A + x) ÷ (T + x), and after missing y classes it is A ÷ (T + y). Set each one to at least t and solve. You round x up and y down because classes come in whole numbers and even a fraction below the target counts as short.
Worked example: from 70% back to 75%
You’ve attended 42 of 60 classes, so your attendance is 42 ÷ 60 × 100 = 70%. To reach 75%:
x = (60 × 0.75 − 42) ÷ (1 − 0.75) = (45 − 42) ÷ 0.25 = 12 classes
| Classes attended in a row | Attended / held | Attendance |
|---|---|---|
| 0 | 42 / 60 | 70% |
| 4 | 46 / 64 | 71.88% |
| 8 | 50 / 68 | 73.53% |
| 12 | 54 / 72 | 75% |
The percentage climbs slowly. Each class you attend also adds one to the total, so it moves by less than a point each time. That is why keeping attendance up is far easier than recovering it. With an 85% requirement, the same student would need 60 classes in a row.
How many classes can I bunk?
Now suppose you’ve attended 54 of 64 classes, which is 84.38%. With a 75% minimum:
y = (54 − 0.75 × 64) ÷ 0.75 = (54 − 48) ÷ 0.75 = 8 classes
Missing 8 in a row leaves you at 54 of 72, exactly 75%. A ninth absence drops you to 54 ÷ 73 = 73.97%. This is your safe number right now, and it assumes no other classes happen in between. If you attend some classes along the way, your budget grows, which is what the next option measures.
Planning for the rest of the term
If you know how many classes are left, the calculator works out a budget for the whole term. Take 42 of 60 again, with 40 classes still to come. The term will have 100 classes, and 75% of 100 is 75, so you must attend 33 of the remaining 40 and can miss 7. The best you can finish with is 82%, if you attend all 40.
At the start of a term, enter 0 for classes attended and held and fill in the classes in the term. For a 90-day semester at 75%, 0.75 × 90 = 67.5, so you need 68 days present and can miss 22.
75% attendance rules in colleges and schools
The 75% figure is common in Indian schools and colleges, but it isn’t universal, and the details change the answer. These rules come from each body’s own documents:
| Institution | Minimum attendance | Details |
|---|---|---|
| CBSE (Classes 10 and 12) | 75% | Needed to sit the board exams. Relaxation only for documented exigencies such as medical emergencies or national sports events. |
| Anna University (R2021, UG) | 75% overall | Rounded to the nearest integer. 65% to 74% may be allowed for medical or sports reasons; below 65% means repeating the semester. |
| VTU (2022 scheme) | 85% in each course | The Vice-Chancellor can condone a shortage of up to 10% on the principal’s recommendation, for reasons such as illness or sports. |
| AKTU (B.Tech. ordinance) | Full attendance expected | Up to 25% can be condoned for medical or other genuine reasons, and up to 15% more with the head of institution’s prior permission. |
The AKTU rule is in its revised B.Tech. ordinance. Two of these differences change the maths. VTU counts each course separately, so run the calculator once per subject. Anna University works out one overall figure from the periods attended across all courses. If your college publishes its own regulations, follow those over any general rule of thumb.
Tips for keeping your attendance safe
- Check whether your college counts attendance per subject or overall. A healthy overall figure can hide one subject below the line.
- Labs and practicals often count as two or three periods. Count periods rather than sessions if that is how your college records them.
- Keep a buffer of two or three classes. Registers are sometimes updated late, and a class you thought was cancelled may still count.
- Some colleges check attendance on a cut-off date before exams, not at the end of term. Use the classes held up to that date.
- Hand in medical certificates on time. Condonation rules need documents, and CBSE’s 2025 circular treats leave without a written request as unauthorised absence.
For other percentage questions, try the percentage calculator. To turn exam marks into a percentage, use the marks percentage calculator, and to track your grades across semesters, use the CGPA calculator.
Attendance Calculator: frequently asked questions
How do I calculate my attendance percentage?
Divide the classes you attended by the total classes held and multiply by 100. If you attended 42 of 60 classes, your attendance is 42 ÷ 60 × 100 = 70%.
How many classes can I bunk and still keep 75% attendance?
Work out (A − 0.75 × T) ÷ 0.75 and round down, where A is classes attended and T is classes held. With 54 of 64, that is (54 − 48) ÷ 0.75 = 8 classes. A ninth absence drops you to 73.97%.
How many classes do I need to attend to get 75% attendance?
Work out (0.75 × T − A) ÷ 0.25 and round up. With 42 of 60 classes, (45 − 42) ÷ 0.25 = 12, and attending 12 in a row gives 54 of 72, exactly 75%.
What does 75 percent attendance mean in days?
Multiply the working days by 0.75 and round up. In a 90-day semester, 75% is 67.5 days, so you must be present on 68 days and can be absent on at most 22.
Is 74.5% attendance counted as 75%?
Only if your rules round. Anna University's 2021 regulations require 75% after rounding to the nearest integer, so 149 of 200 classes (74.5%) would normally round up to 75% there. Where no rounding is stated, 74.5% is short.
What happens if my attendance is below 75%?
It depends on the institution. CBSE does not let students below 75% sit the board exams except for documented exigencies such as medical emergencies. Anna University can allow 65% to 74% for medical or sports reasons with a certificate, and students below 65% repeat the semester.
How many classes can I miss for 80% or 85% attendance?
Change the required attendance to 80 or 85. With 54 of 64 classes (84.38%), you can miss 3 classes and stay above 80% (54 of 67 is 80.6%), but you are already below 85% and need 3 classes in a row to reach it (57 of 67 is 85.07%).
How do I calculate attendance percentage in Excel?
With classes attended in B2 and classes held in C2, use =B2/C2*100 for the percentage, =ROUNDUP((0.75*C2-B2)/0.25,0) for the classes needed to reach 75%, and =ROUNDDOWN((B2-0.75*C2)/0.75,0) for the classes you can miss. Wrap the last two in MAX(0, …) so they never show a negative number.
How we checked this page: every figure in the examples and FAQs above is produced by this calculator and verified by automated tests against known answers, and the rules and rates come from the sources below. Last updated . Spotted a problem? Tell us.