This article briefly introduces the definition of budget and how it works.
Budget is the total amount of money you are willing spend for running ads, and can be a great tool for cost control. While bidding is used for controlling the cost per result as the ad level, budgeting is used to control the overall costs for campaigns and ad groups.
You can set budgets for both campaigns and ad groups (one campaign can consists of several ad groups). There are 2 types of budgets, lifetime budgets and daily budgets.
Note: Once you publish your campaign, you cannot change the budget type at the campaign or ad group level. As such, you will be unable to switch from a daily budget to a lifetime budget and vice versa.
The lifetime budget is the maximum amount you are willing to spend on a campaign or ad group during the entire defined period you run an ad.
Please note that when using lifetime budget on the ad group level, the delivery system will try to distribute the spending of your budget to run throughout the entire provided time range, but it is not guaranteed to allocate the budget exactly evenly on day-to-day. If you would like to set a daily spending cap, please use the daily budget instead.
The daily budget is the maximum you are willing to spend on a campaign or ad group per day.
Lifetime and daily budgets are set as upper limits and the amount actually spent during the delivery period can be less than the budget amount you specified. However, the cost of your campaign or ad group will never exceed the budget you set.
Please keep in mind that if you select "Daily Budget" for a campaign, you must select "Daily Budget" at the ad group level. If you select "Lifetime Budget" for a campaign, you can select either "Daily Budget" or "Lifetime Budget" at the ad group level.
A minimum budget is required when setting both lifetime budgets and daily budgets in order to ensure the continuous delivery of your ad.
Campaign level minimum budget: For campaigns, both daily budgets and total budgets must exceed 50 USD.
Ad group level minimum budget: For ad groups, daily budgets must exceed 20 USD. Lifetime budgets will be calculated as the minimum daily budget (20 USD) × scheduled days.
For example: If delivery is scheduled for 31 days, the minimum budget for the ad group would be 20 USD × 31 days = 620 USD.