Attendance Percentage Calculator — How Many Classes Can You Miss?

attendline makes the 75% line visible. Enter how many classes you have attended and how many were held, and it shows your exact attendance percentage, how many classes you can still miss, or how many you must attend in a row to get back over your cutoff. The percentage is truncated, never rounded up, so it never overstates how safe you are.

The two formulas

• Can-miss: the largest number of future classes m where attended ÷ (held + m) is still at least your cutoff.
• Must-attend: the smallest run of classes k (attending every one) where (attended + k) ÷ (held + k) first reaches your cutoff.

Both use exact integer cross-multiplication — attended × 10000 ≥ cutoff_bp × held — never the rounded display number.

Worked example

You have attended 68 of 80 classes: that is 85.00%. At a 75% cutoff you can miss 10 more (68/90 = 75.55%, but 68/91 = 74.72%). A subject at 50/72 is 69.44% — below the line — so you would need to attend 16 in a row to reach 66/88 = 75.00%.

Honest limits

Your college's rules win. Cutoffs, condonation, and medical waivers vary by institution; attendline computes arithmetic, it does not certify eligibility. Every class counts equally here. It is framed as attendance safety — it shows your margin, it does not encourage using it.

Try it below

The calculator below is loaded with a sample semester. Edit it or add your own subjects — nothing you type leaves this page.