Time allocation in conference presentations How much time should I expect to 'leave' at the end of a conference presentation for questions? This question suggests to allocate 2-3 minutes per slide, including front/back matter (like a question slide). Does this mean I should leave 2-3 minutes for every 15 minutes of presentation delivered? Is there a good 'rule of thumb' for this?
The only rule of thumb I'm familiar with is a bit like this, keeping in mind that some of the additional time may serve as buffer in case there are questions during the talk:


For talks of or less than 30 minutes total, include no less than 5 and no more than 10 minutes for questions.
For talks between 30 and 60 minutes, include no less than 10 and no more than 15 minutes for questions.


So that essentially means at least 5 minutes for each half hour (not too far off from your estimates).

For longer talks, there never seems to be enough time for questions, so I would suspect there isn't one rule for all situations.