It depends. Originally when I first started it took me a while to edit my videos. I usually record around 30-40 minutes and then edit down to 15-20 minutes. So when i first started editing it took a few hours, but now I can do a video just under 2 hours.How long does it take you roughly to edit a video? This video that i've done is 24 minutes long, its took over 4 hours to edit and i've just finished it.
When i do the MGN top 5's they can take a tad bit longer then 2 hours but still. I believe it depends on the knowledge and shortcuts of the software plus also knowing what you want to do and how much editing a video requires.