Your average daily budget is the average amount that you set for each ad campaign on a per-day basis. It specifies how much you’re roughly comfortable spending each day over the course of the month. You can set and edit your average daily budget at any time.

Google will optimise your campaign spend for days of the month when you’re more likely to get clicks and conversions, like when search traffic is higher or when we predict higher ROI for your ads. This means that on some days you might not reach your average daily budget, and on others you might exceed it.

Even though your campaign spend might vary, you’ll never pay more than:

• Your daily spending limit (two times your average daily budget for most campaigns) on any particular day.
• Your monthly spending limit (30.4 times your average daily budget for most campaigns) in any particular month.