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.