That depends on a few factors, including the type of ad (such as a text ad or a commercial), how popular the video is and what company sold the ad (such as Google’s ad sales division or YouTube’s ad sales division). You’ll be able to log into your own YouTube account and see the information and know exactly how much you are making off of each view.
YouTube has written up a lot of information about their different types of ads. You can read more about them here.