Attendance percentage calculator with the 75% rule built in

How attendance percentage is calculated

Attendance percentage is the share of sessions a student was present for, out of all sessions held in the period:

Attendance % = (classes attended ÷ classes held) × 100

A student who attended 84 of 120 classes has 84 ÷ 120 × 100 = 70% attendance. Whether 70% is enough depends on the rule your school, board or university applies. 75% is the most common minimum in India for board-exam eligibility and in most colleges and universities.

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

If you're below the target, you need some number of consecutive classes, x, so that (attended + x) ÷ (held + x) reaches the target t (as a decimal, so 75% = 0.75):

x = (t × held − attended) ÷ (1 − t), rounded up

Worked example: 84 of 120 at a 75% target gives (0.75 × 120 − 84) ÷ 0.25 = 6 ÷ 0.25 = 24 more classes in a row. After them you'd be at 108 of 144, exactly 75%.

How many classes can I miss and still stay above 75%?

If you're above the target, the number of upcoming classes y you could miss is the largest y where attended ÷ (held + y) is still at or above the target:

y = (attended ÷ t) − held, rounded down

Worked example: 100 of 120 at 75% gives 100 ÷ 0.75 − 120 = 133.3 − 120 = 13 classes. Miss a 14th and you drop below the line.

Quick reference: attendance needed to reach 75%

The number of classes a student must attend in a row to climb back to 75%, from a few common starting points.

Common minimum-attendance rules

Rules vary, so always check the current circular from your own board, university or school. In general:

• Indian school boards: boards such as CBSE expect around 75% attendance for a student to sit the board exams. Shortfalls can be condoned for documented reasons such as medical emergencies, usually at the principal's or board's discretion.
• Colleges and universities in India: 75% per subject is the most common threshold. Some institutions allow condonation down to 65% with medical proof, sometimes with a fee.
• Schools elsewhere: many systems track "persistent absence" rather than a pass mark. In England, for example, missing 10% or more of sessions (attendance of 90% or below) is classed as persistent absence.

Medical leave, approved leave and school events are usually handled differently from plain absence. Some institutions count approved leave as present, while others exclude those days from the total held. If your school uses a different convention, adjust "classes held" to match it before you calculate.

For teachers: calculating attendance for a whole class

The same formula works per student, per subject or per month. Doing it by hand for 40 students every month is where errors creep in: a wrong column total, or a holiday counted as a working day. In Premeena's attendance module you mark the register once (by hand, or by scanning the class with a camera). The monthly view and each class's attendance summaries then update on their own, and parents of absent students get an email and push alert when the register is finalised.

Frequently asked questions