Google Ads Budgets and Bid Strategies

Our Google Ads basics guide covers the auction, Quality Score and keywords. This guide goes deeper into the two settings that control spend. All facts below come from Google Ads Help pages, linked where they are used.

The average daily budget

Every campaign has a budget. Google's page on average daily budgets defines it as "the average amount that you set for each ad campaign on a per-day basis", and says it specifies how much you are roughly comfortable spending each day over the course of the month.

The word average matters. Google says it optimizes spend for the days when you are more likely to get clicks and conversions, such as when search traffic is higher. So on some days a campaign spends less than the budget and on others it spends more. You can change the budget at any time and as often as you like, but Google notes that a change can affect your spending limits and how often your ads show.

The same page mentions shared budgets, which let you set one budget across several campaigns. They suit a few small campaigns with the same goal, where you would rather let spend move to whichever campaign is doing well than split a small amount in advance.

Daily and monthly spending limits

Because spend varies by day, Google puts two caps on it. According to its budget page, you will never pay more than:

• A daily spending limit: two times your average daily budget for most campaigns, on any particular day.
• A monthly spending limit: 30.4 times your average daily budget for most campaigns, in any particular month.

Spending more than the budget on one day is called overdelivery. Google's overdelivery page says a campaign might spend up to twice its average daily budget "to take advantage of fluctuations of traffic", and that by the end of the month you will have spent no more than 30.4 times the daily budget. It also explains that the cost of the clicks a campaign received (served cost) can sometimes go over the limits, but you are never billed more than the limits. The Billed cost report in the Report editor shows served and billed cost side by side.

In practice: do not judge a campaign by one expensive day. Look at spend over the month, and set the daily budget at a level where a day at double it would still be acceptable.

Working from a monthly budget

Most businesses think in monthly amounts. Google's instructions for setting a daily budget say to divide a monthly budget by 30.4, the average number of days in a month. Its own example: a $304 monthly budget becomes a $10 average daily budget, and a campaign left at $10 a day for a whole month can be charged at most $304 for that month, as its page on managing spend explains.

If you split one monthly amount across several campaigns, decide the split by goal first (for example, most of it on the campaign that brings enquiries) and review it after a few weeks of data, not after a few days.

If an ad schedule switches a campaign off on some days of the week, note that since June 1, 2026 Google still paces it towards the 30.4-day monthly limit. Our Google Ads ad scheduling guide explains what that means for the daily budget.

Bid strategies by goal

The bid strategy decides how much the campaign offers in each auction. Google's guide to choosing a bid strategy starts from the goal:

• Direct actions on your site (calls, forms, sales), with conversion tracking set up: focus on conversions with Smart Bidding.
• Traffic to your website: focus on clicks with cost-per-click bidding.
• Brand awareness: focus on impressions, for example with viewable CPM (vCPM) bidding.
• Video views or interactions: cost-per-view or CPM bidding for video ads.

For a business that wants enquiries or sales, conversions are the goal, which means conversion tracking comes first. Google notes that for conversion-focused bidding the conversion actions you want to optimize for should be set as Primary. Our Google Ads conversion tracking guide covers the setup, and offline conversion import covers sales that close by phone or in person.

Smart Bidding

Google's Smart Bidding page describes it as bid strategies that use Google AI to optimize for conversions or conversion value in every auction, which Google calls auction-time bidding. The bid takes signals such as device, location, time of day, language and operating system into account. There are four Smart Bidding strategies:

• Maximize conversions: aims to get the most conversions while spending your budget. Google's Maximize conversions page warns that it will try to fully spend your average daily budget, so if you currently spend much less than the budget, spend could increase significantly.
• Target CPA: you set the average cost per conversion you want, and Google sets bids to get as many conversions as possible at that target. Its Target CPA page recommends checking that you are comfortable spending up to 2 times your average daily budget, and says setting bid limits is not recommended because it can restrict the optimization.
• Maximize conversion value: aims for the highest total conversion value (for example revenue) within the budget, and also tries to fully spend it, per Google's Maximize conversion value page.
• Target ROAS: you set a target return on ad spend, and Google bids higher on searches likely to bring a high-value conversion and lower on others. Its Target ROAS page says you need to set values for the conversions you track first.

The two "Maximize" strategies spend the budget; the two "Target" strategies aim at an efficiency goal. Google notes that if you have a specific return-on-investment goal, the target versions are the ones to use. One naming change to know: Google says that starting in June 2026, "Maximize conversions with a Target CPA" is being renamed "Target CPA", and "Maximize conversion value with a Target ROAS" is being renamed "Target ROAS", so older articles and screenshots may use the longer names.

Target CPA and Target ROAS can run on a single campaign or as a portfolio strategy shared by several campaigns, which are then optimized together for one target. Google notes portfolio strategies are not available for Performance Max campaigns, which our Performance Max guide covers.

Bidding for clicks and visibility

Not every campaign has enough conversions to bid on. For clicks, Google offers:

• Maximize clicks: sets bids to get as many clicks as possible within the budget. Google's Maximize clicks page says you can set a maximum CPC bid limit to cap what you pay per click, but that if the limit is too low, the strategy may not be able to get the clicks you want. Google suggests this strategy for new campaigns that lack the conversion data for Target CPA or Target ROAS.
• Manual CPC: you set the maximum cost-per-click yourself, with a default bid for each ad group and, if you want, separate bids for individual keywords, according to Google's manual CPC page. It gives the most control but takes regular work.
• Target impression share: for Search, sets bids with the goal of showing your ad at the absolute top of the page, the top of the page or anywhere on the page of results. It is about visibility, not results, so use it with care. Our guide to auction insights explains impression share and the competitor report.

What happened to Enhanced CPC

Enhanced CPC (ECPC) used to adjust manual bids up or down for clicks that seemed more or less likely to convert. Google's ECPC page now says that effective the week of March 31, 2025, ECPC is no longer available for Search and Display campaigns, and campaigns that were not moved to another strategy before then are effectively using Manual CPC. If an older campaign of yours still shows ECPC, it is worth choosing a current strategy on purpose.

Choosing a strategy for a small account

Google does not publish one right answer, and the right choice depends on your data. A practical way to apply its guidance:

• No conversion tracking yet: set it up first. Until then, Maximize clicks with a sensible maximum CPC limit, or Manual CPC if you want control by keyword.
• Tracking works, conversions are few: Maximize conversions is the simplest Smart Bidding start. Expect it to use the whole budget, so set a budget you are happy to spend.
• A steady flow of conversions and a known cost per lead you can afford: Target CPA, set close to what the campaign achieves now, then adjust slowly.
• Sales with different values: Maximize conversion value, then Target ROAS once you know the return you need.

Whatever you choose, change one thing at a time and give it time before judging. Check that the search terms you pay for are relevant too; our guide to search terms and negative keywords shows how. Smart Bidding can only optimize toward what your conversion tracking counts, so a form spam problem or a duplicate conversion skews the bids directly. The Recommendations page will also suggest bid strategy and budget changes; our guide to recommendations, auto-apply and optimization score explains how to judge them.

FAQ

Why did Google Ads spend more than my daily budget?

Google allows a campaign to spend up to two times its average daily budget on a single day for most campaigns, which it calls overdelivery. Over a month you will not be charged more than 30.4 times the average daily budget.

How do I turn a monthly budget into a daily budget?

Divide the monthly amount by 30.4, the average number of days in a month. Google's example is a 304 dollar monthly budget, which becomes a 10 dollar average daily budget.

What is the difference between Maximize conversions and Target CPA?

Maximize conversions tries to get the most conversions while spending your full budget. Target CPA aims for as many conversions as possible at the average cost per conversion you set. Google suggests the target version if you have a specific return-on-investment goal.

Which bid strategy should a new campaign use?

Google says Maximize clicks can be useful for new campaigns that lack enough conversion data for Target CPA or Target ROAS. Set up conversion tracking from the start so you can move to Smart Bidding once conversions come in.

Can I still use Enhanced CPC?

No, for Search and Display. Google says Enhanced CPC is no longer available for those campaigns from the week of March 31, 2025, and campaigns that were not switched are effectively using Manual CPC.

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