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Attendance calculator

  

Every class counts the same. The percentage you need is set by your college or board, commonly 75%.

%

Attendance

68.89%

You are below 75%. Attend the next 22 classes in a row, with no absences, to reach it.

Classes to attend in a row
22
ShortSafe

The maths behind the 75% rule

Attendance rules look simple until you are 4 percentage points short with six weeks to go. The answer is not 4 more classes. Every class you attend raises both the top and the bottom of the fraction, so you need more than you expect.

Say you attended 62 of 90 classes, which is 68.89%. To reach 75% you must attend the next 22 classes without missing one. After that you have 84 of 112, exactly 75%. The formula is (75 × 90 − 100 × 62) ÷ 25 = 22.

The other direction is just as useful. With 80 of 100, you are at 80%, and you can miss 6 more classes in a row. After that you would have 80 of 106, which is 75.5%. A seventh absence takes you under 75%.

A practical rule: do not treat the margin as free days. Attendance often affects internal marks, exam eligibility and hall tickets. If you do fall short, ask about condonation. Many colleges allow it with a medical certificate or an application and a fee.

Sources

What this calculator does not account for

  • Condonation rules.
  • Classes of different length.
  • Medical leave and grace rules.

How this is calculated

Formula: Classes to attend or miss

to attend =⌈(req × total − 100 × attended) ÷ (100 − req)⌉; can miss =⌊attended × 100 ÷ req − total⌋

What the symbols mean

  • reqThe attendance percentage required, such as 75.
  • totalClasses held so far.

Good to know

  • The attend formula assumes you go to every class from now on.
  • The miss formula assumes you attend none of the next classes you skip.

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Worked examples

Each example is worked out by the same code as the calculator above.

62 of 90 classes, 75% required

Attendance 68.89%. Attend the next 22 classes in a row to reach 75%.

80 of 100 classes, 75% required

Attendance 80%. You can miss 6 more classes and stay at or above 75%.

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Questions

How do I calculate attendance percentage?

Classes attended divided by classes held, times 100.

How many classes do I need to attend for 75%?

Enter your numbers above. For 62 of 90, it is 22 in a row.

Is 75% the rule everywhere?

It is common in Indian universities and colleges, but many set 80% or 85%, and some allow condonation with a medical certificate.

Does missing a class count the same as a late arrival?

That depends on your institution. This tool counts each class as attended or not.