When you already know how much you’d like to spend on your entire video campaign, you can set a campaign total budget. You’ll have the option to select “Campaign total budget” while creating your new video campaign.
Keep in mind that you can’t change the budget type once a campaign is created.
Google Ads will try to spend your total budget evenly over the duration of your campaign while taking into account higher and lower traffic days to optimize your campaign’s performance. For example, let’s say your video campaign gets fewer views on Mondays and Tuesdays and more views on weekends. Google Ads will optimize performance by spending more on days when your video is likely to get more views, while keeping your overall budget goals on track.
With a campaign total budget, you’ll only be billed up to the amount you enter for a campaign, even if Google Ads serves more views or impressions than your budget allows.