Sri Lanka University Attendance Calculator

The calculator uses the standard definition of attendance every Sri Lankan university applies: your attendance percentage is the number of classes you attended divided by the number of classes conducted, times 100. Everything else follows from that single ratio and the minimum threshold your faculty sets — 80% by default, under the University Grants Commission (UGC) common examination by-law framework.

Let a be classes attended, c classes conducted so far, and p your required minimum as a fraction (0.80 for 80%). The tool computes four things:

1. Current attendance = a ÷ c × 100. Colour-coded green when you clear the bar, amber when you're within five points of it, red when you're below.
2. How many more you can skip — the largest whole number m where a ÷ (c + m) ≥ p. Each class you miss adds to the denominator but not the numerator, so m = floor(a ÷ p) − c, never below zero.
3. How many you must attend to recover— when you're already below the bar, the smallest run of upcoming classes you must attend (missing none) so that (a + x) ÷ (c + x) ≥ p. Solving gives x = ceil((p·c − a) ÷ (1 − p)).
4. Semester planner — if you enter the total classes T planned for the module, the tool works out the minimum you must attend over the rest of the term (ceil(p·T) − a, capped at the classes remaining), the maximum you can still miss, and whether the threshold is even reachable by the end.

All four formulas are pure arithmetic from the attendance definition — there is no hidden weighting or rounding trick. Every boundary is computed with integer-safe comparisons so the answer is exact even at the exact percentage cutoff, where an off-by-one would otherwise creep in. The 80% default is sourced from University of Moratuwa and SLIIT academic regulations; because faculties differ, the threshold is yours to change.

• University Grants Commission (UGC) of Sri Lanka — common examination by-law framework
• University of Moratuwa — degree by-laws and student handbook (80% attendance rule)
• SLIIT — academic regulations and student handbook (attendance requirement)
• University of Colombo, Faculty of Medicine — attendance requirements for lectures and clinical work

The 80% default and its statutory basis were last reviewed on 2026-07-10. Minimum-attendance rules are set per faculty and can change — always confirm the exact figure in your current student handbook.