How many days can you miss?
Percentages are abstract; days are not. Enter the length of the year or term and the attendance you want to hold, and this says how much you can afford to miss.
Calculator
How this is worked out
Multiply the sessions in the period by the target percentage, round up to the next whole session — you cannot attend four fifths of a registration — and subtract that from the total. What is left is how many sessions can be missed.
Rounding up matters: it is the difference between hitting your target and just missing it.
Sessions, days and weeks
English schools register twice a day, so a day is two sessions and a 190-day year is 380. This page shows the answer in sessions, days and school weeks, because a figure like “nineteen sessions” means very little until you hear it as “about two weeks”.
The numbers people are usually surprised by
| Attendance over a full year | Days missed |
|---|---|
| 95% | 9.5 days — about two school weeks |
| 90% | 19 days — about four school weeks |
| 85% | 28.5 days — about six school weeks |
| 80% | 38 days — about eight school weeks |
Ninety per cent sounds respectable and is the line the Department for Education calls persistent absence. Four weeks of a year is what it buys.
Authorised days count too
A day signed off as illness still comes out of this allowance. Authorising an absence records that the reason was accepted; it does not put the day back.