There is no specific total time for an AFL quarter.
The time is 25 minutes of the ball on field, whenever the ball is out of bounds, heacing back to the middle after a goal, or whenever, the clock still counts up but is not counted in the 25 minutes total. This means that some quarters can be over half an hour. The longest quarter I've seen was forty minutes long.
Chat with our AI personalities
An AFL quarter is 20 minutes of actual play. However the clock is stopped several times during a quarter for things such as returning the ball to the centre after a goal. Ball ups when the ball takes a long time to get to the field umpire, significant injuries to players (especially if a stretcher is required). From siren to siren a quarter is around 30 minutes long but anywhere from 26 to 33 is not unusual.
There is 20 minutes playing time in each quarter. This doesn't include stoppages. For example, if play stops for an injured player this time is added on to the end of the quarter. Also, when the ball is kicked into the crowd for a goal, the time taken to return the ball to the centre of the field is not counted. A quarter with a high number of goals will go longer for this reason.