> Quick answer: Google Ads does not have a feature called CBO. That term belongs to Meta. Google offers three budget models: Average Daily Budget, Campaign Total Budget, and Shared Budget. For multi-campaign optimization that mirrors Meta's CBO logic, pair Shared Budgets with Portfolio Bid Strategies.
What Is Budget Optimization in Google Ads?
Budget optimization in Google Ads means letting the platform allocate your spend where it performs best. Google does this automatically, across days and campaigns. The goal is always the same: more conversions for the same total spend.
Google Ads vs. Meta: Clearing Up the CBO Terminology
CBO is a Meta term. It does not exist in Google Ads. If you searched for a "CBO" toggle inside Google Ads, there isn't one.
Why Google Ads calls it different names
CBO (Campaign Budget Optimization) comes from Meta. Facebook introduced it to let advertisers set one campaign-level budget and let the algorithm distribute spend across ad sets. Google Ads was built with different budget logic from the start. Google never adopted the CBO label.
What Google offers instead of CBO
Per Google's Ads Help Center, Google Ads offers three budget types: Average Daily Budget, Campaign Total Budget, and Shared Budget. For multi-campaign optimization, Shared Budgets paired with Portfolio Bid Strategies come closest to what Meta calls CBO.
Google Ads' Three Budget Models Explained
Google gives you three distinct ways to control spend. Each fits a different campaign structure and goal.
Average Daily Budget: For ongoing, flexible campaigns
You set a daily target. Google spends more on high-traffic days and less on slow ones. You never pay more than 2x your daily budget in a single day, or more than 30.4x your daily budget in a single month.
Campaign Total Budget: For time-bound, fixed-spend campaigns
You set a total amount for the full campaign flight. Google distributes that spend across the campaign duration. No daily spending limits apply.
Shared Budget: For multi-campaign allocation
One average daily budget shared across multiple campaigns. Google automatically shifts unspent budget from slower campaigns to better-converting ones.
When to Use Average Daily Budget
Average Daily Budget is the right default for most ongoing campaigns.
Best use cases
Use it for always-on search campaigns, evergreen brand awareness, or any campaign with no fixed end date. If you want consistent daily spend with no hard cutoff, this is your model.
How Google optimizes spend day-to-day
Per Google's Ads Help Center, Google forecasts traffic patterns and adjusts daily spend to match. High-traffic days get more budget. Quieter days get less. The average stays close to your daily target.
Spending limits and overdelivery
Google may spend up to 2x your daily budget on a busy day. But you will never be charged more than 30.4x your daily budget in a single month. That is your built-in ceiling against overdelivery.
When to Use Campaign Total Budget
Campaign Total Budget is purpose-built for campaigns with a fixed end date and a hard spend cap.
Best use cases (seasonal, promotional, time-limited events)
Black Friday sales. Product launches. Event promotions. Any campaign with a defined start and end date benefits here. You control the total spend, and Google handles the daily pacing.
How it differs from daily budgets
There are no daily spending limits with Campaign Total Budget. Google decides how to pace spend across the campaign window. Some days will be heavier, some lighter, depending on forecast traffic.
Time and spend constraints
Per Google Ads documentation, Campaign Total Budgets require a minimum 3-day campaign duration. The maximum is 90 days for most campaign types, and up to 1 year for Demand Gen and YouTube campaigns. This budget type is only available when creating a new campaign. You cannot change it after launch.
When to Use Shared Budget
Shared Budget makes sense when multiple campaigns are chasing the same conversion goal.
Best use cases (multi-campaign strategies with shared goals)
Running several search campaigns across different product lines? Set a Shared Budget. Google automatically moves money to whichever campaign is converting best on any given day. No manual reallocation needed.
Combining shared budgets with Portfolio Bid Strategies
Per Google's Ads Help Center, customers who combine Shared Budgets with Portfolio Bid Strategies on Search campaigns see an average of +13% more conversions. Google optimizes both bids and budget allocation at the same time. The two tools reinforce each other directly.
Campaigns that qualify for shared budgets
Shared Budgets work with most standard campaign types. They do not work with Performance Max, Smart Shopping, Hotel (Commission) campaigns, or campaigns running in experiments. They also cannot be combined with Campaign Total Budgets.
How Portfolio Bid Strategies Amplify Budget Optimization
Portfolio Bid Strategies are the other half of Google's multi-campaign optimization equation.
What portfolio bid strategies do
Per Google's Ads Help Center, Portfolio Bid Strategies are AI-powered, goal-driven bid strategies. They group multiple campaigns, ad groups, and keywords together. Google AI then sets bids to hit a shared performance goal across all grouped assets at once.
Best performing combinations
Pair a Shared Budget with a Target CPA or Target ROAS Portfolio Bid Strategy on Search campaigns. Google then controls both where budget flows and how aggressively to bid in each auction. That combination is the closest Google Ads equivalent to Meta's CBO.
Performance gains with shared budgets
The +13% conversion lift cited by Google applies specifically to Search campaigns using Shared Budgets and Portfolio Bid Strategies together. Individual results vary by industry, account history, and campaign quality.
Budget Optimization Checklist: Choosing the Right Model for Your Goals
Use this to pick the right budget type fast.
Average Daily Budget — choose this if:
- Your campaign has no end date
- You want predictable daily spend
- You are running a single campaign
Campaign Total Budget — choose this if:
- You have a fixed total spend cap
- Your campaign runs 3 to 90 days (or up to 1 year for Demand Gen/YouTube)
- You are setting up a new campaign and do not need to change the budget type later
Shared Budget — choose this if:
- You are running multiple campaigns toward the same goal
- You want Google to auto-shift spend to top performers
- You plan to pair it with a Portfolio Bid Strategy
One important constraint: Campaign Total Budget and Shared Budget are mutually exclusive. Pick one. Shared Budgets use the Average Daily Budget model and cannot be mixed with Campaign Total Budgets.
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Frequently Asked Questions
Does Google Ads have a CBO feature?
No. CBO (Campaign Budget Optimization) is a Meta term for Facebook and Instagram campaigns. Google Ads uses different budget models: Average Daily Budget, Campaign Total Budget, and Shared Budget. For multi-campaign optimization that works similarly to Meta's CBO, use Shared Budgets combined with Portfolio Bid Strategies.
What is the difference between a Shared Budget and a Campaign Total Budget in Google Ads?
A Shared Budget is a single average daily budget distributed automatically across multiple campaigns. Google shifts unspent budget to better-performing campaigns. A Campaign Total Budget is a fixed total spend cap for one campaign over a set time period (3 to 90 days). They cannot be used together.
Can I use a Shared Budget with Performance Max campaigns?
No. Per Google's Ads Help Center, Shared Budgets are not compatible with Performance Max campaigns, Smart Shopping campaigns, Hotel (Commission) campaigns, or campaigns running in experiments. Use a standard Average Daily Budget for those campaign types.
What is a Portfolio Bid Strategy and why does it pair well with Shared Budgets?
A Portfolio Bid Strategy is an AI-powered bid strategy that groups multiple campaigns, ad groups, and keywords together and optimizes bids toward a shared performance goal. Pairing it with a Shared Budget lets Google optimize both budget allocation and bid amounts at once. Per Google's Ads Help Center, this combination delivers an average of +13% more conversions for Search campaigns.