what happens when you change your daily budget

Do you know how much Google can charge you when you make changes to your daily budget setting?

I had to look up the exact details myself today, so I might as well share the answers with you 🙂

First, some definitions and theory.

Your average daily budget:
The average budget amount that you set for each ad campaign on a per-day basis. It specifies how much you are roughly comfortable spending each day over the course of the month.

Your daily spending limit:
The max amount you pay on an individual day.

Your monthly spending limit:
The max amount you pay for the given month.

Your daily spending limit is 2x your average daily budget, because of Google’s disputable over-delivery feature. Your monthly spending limit is 30.4 times your average daily budget (because 30.4 is the average number of days in a month).

Now… what happens when, today, you make a change in the daily budget setting?

The impact on your daily spending limit:
On the day you make a change (or more than one change) to your average daily budget, your daily spending limit will be based on the highest average daily budget that you chose for that day. So, let’s say you have a campaign with an average daily budget of US$100. On the same day, you first increase your budget to $150, and then lower it to $75. The daily spending limit for the day is going to be the highest of your average daily budgets multiplied by 2, therefore $150 * 2 = $300.

The impact on your monthly spending limit:
When you change your budget, your spend for the rest of the month won’t exceed your new average daily budget multiplied by the remaining days in the month. Let’s look at a hypothetical monthly spending limit for this month Jan 2022, which spans from Jan 1 to Jan 31. On Jan 1, you set an average daily budget of $500, for a monthly spending limit of $15200 ($500 * 30.4). Then assume that today, Jan 13, you’ve only spent $5000 and you decide to increase your average daily budget for the remaining days of the month. You then change your average daily budget to $600. The maximum you’ll be charged for the month of January will be: $5000 spent so far + ($600/day * 19 days remaining in January) = $16400 monthly spending limit.

As you can see, pacing budgets via the daily budget setting is far from easy but also no rocket science. 

This is also something that highly benefits from automation, so be sure to check out these scripts to help you manage your budgets:

https://nilsrooijmans.com/daily-budget-overdelivery-alerts-script/

https://nilsrooijmans.com/top-5-google-ads-scripts-for-budget-management/

– Nils

Author: Nils Rooijmans

Google Ads Performance Architect with a passion for PPC Automation & AI, in particular via Google Ads Scripts.