One of your clients wants to know why a campaign went over the specified daily budget several days in a row
Correct Answer
Due to changes in traffic, Google Ads allows up to 20% more clicks in a day than the budget specifies. However, in any given month, Google Ads never charges more than the average daily budget amount multiplied by 30.4
Why is this the correct answer?
A campaign can go over its specified daily budget because Google Ads allows up to 20% more clicks in a day than the budget specifies when traffic is higher than usual — but in any given month, Google Ads never charges more than the average daily budget multiplied by 30.4. This overdelivery on individual days is balanced out by underdelivery on slower days, ensuring the monthly total stays within budget. The 30.4 multiplier ensures advertisers never exceed what a month of daily budget would imply.
Why are the other options incorrect?
Google Ads automatically increases the maximum cost-per-click (CPC) bid to show an ad higher in Google search results
Google Ads does not automatically increase max CPC bids to show ads higher — bids are only changed if the advertiser uses automated bidding strategies, not as a default behaviour when budgets are exceeded.
Due to changes in traffic, Google Ads allows up to 20% more impressions in a day than the budget specifies
The overdelivery allowance is 20% more clicks, not 20% more impressions — and it is balanced across the month so the total monthly spend does not exceed the daily budget x 30.4.
To show an ad more often, Google Ads charges more than the average daily budget amount multipled by 30.4
Google Ads never charges more than the average daily budget multiplied by 30.4 in a month — this answer incorrectly implies charges above that monthly equivalent.
Real-World Example
A retailer sets a £50/day budget. On Black Friday, traffic surges and Google delivers £60 of clicks — 20% over the daily budget. However, on quieter days earlier in the month the campaign spent only £35-40/day. The total monthly spend is £1,520 — exactly within the £50 x 30.4 = £1,520 monthly cap.