It will depend on a few things: size of the video, Internet connection type, Internet upstream/downstream speed and also video compression. The best thing to do is to import your video into and editing program (if you have a Mac then you can use iMovie) you don’t have to make any edits, just import it and then save/export. This will compress the footage and allow it to upload faster to YouTube/Vimeo…or wherever you are posting it.