Once you've set up an account spending limit, you'll be able to see a real-time estimate of the amount that you've spent towards your limit in your payment settings:

The "amount spent" here won't include any amount that you spent on ads before you set up your limit. It'll just show what you've spent since you created or last changed your limit. This is why the amount here may differ from your account's lifetime amount spent or what you see in the Billing section of Ads Manager.

Bear in mind that your account spending limit is different from a lifetime budget (which controls how much an ad set can spend over its lifetime) and your billing threshold (which determines when you're charged for your ads). Learn more about the difference between budgets, your billing threshold and spending limits.

Amount spent in Ads Manager

The "Amount Spent" in the Account overview section of your Ads Manager lets you see the total amount of money you've spent across all your campaigns during a time period you choose. Bear in mind that this is also an estimate because it can take up to 48 hours for ad results to be processed.

Charges in the Billing section of Ads Manager

When you make a payment for your Facebook ads, the transaction will appear in the Billing section of your Ads Manager. Every transaction includes a receipt that shows details about your payment, such as how much you spent, the reason you were billed, the campaigns that spent money and the results your ads got you. Learn more about viewing your Facebook ad charges and payment history.

* Nguồn: Facebook