About campaign budgets and ad set budgets: why Meta's Advantage+ campaign budget may not spend equally

Advantage+ campaign budget is not meant to split your money evenly. Meta's About Advantage+ campaign budget page says it "may not spend your budget equally for each ad set", and that with two active ad sets "we might spend most of your budget on one ad set if that's how we can get the overall best results." Meta's troubleshooting page goes further: "With Advantage+ campaign budget, it's normal for some ad sets or ads to deliver less than others, as long as your overall campaign is spending budget according to the goals you've set."

If an ad set must get money, Meta's controls are a per-ad-set minimum spend limit (which Meta calls "a target range, not a guarantee", though one of its examples reads as a hard floor), or switching to ad set budgets. If you want ads or ad sets compared on equal terms, Meta's answer is an A/B test.

About Advantage+ campaign budget: what is it?

Meta's About Advantage+ campaign budget page:

Advantage+ campaign budget (also known as Campaign budget, or Budget with Advantage+ on) automatically manages your campaign budget across ad sets to get you the overall best results. With Advantage+ campaign budget, you set one central campaign budget. This budget continuously distributes in real time to ad sets with the best opportunities, throughout the course of your campaign.

It is what Meta used to call campaign budget optimization. Meta's reporting page puts it this way: "Meta Advantage+ campaign budget (previously known as campaign budget optimization)".

For many campaigns it is already on. Meta's setup page: "Sales, Leads, and App promotion campaigns will have Advantage+ campaign budget enabled by default." And on Meta's page about what turns Advantage+ on and off, the Budget section shows Advantage+ off "if you have multiple ad sets in your campaign and are not using campaign budget."

About campaign budgets and ad set budgets: which should you use?

Meta's About campaign budgets and ad set budgets page offers three budget strategies (Advantage+ campaign budget, ad set budget sharing, and ad set budgets) and lists "goals to consider" for each. Side by side, for the two main ones:

The line that decides most cases is the last goal in the left column: "You value all ad sets the same." If one ad set is a new market, a priority product or a test you have to fund, you don't value them the same, and Meta's list points you to ad set budgets or to spend limits.

The same page describes how the two spend differently: "While Advantage+ campaign budget spends your overall budget over the course of your campaign, ad set budgets can be spent as soon as delivery opportunities become available for that ad set."

Why doesn't Advantage+ campaign budget spend equally across ad sets?

Because it is built to get the most results for the campaign, not for each ad set. Meta's Understand Advantage+ campaign budget results page names two things that tilt the split:

If your audiences are significantly different in size, ad sets with the largest audiences will likely receive the most budget with Advantage+ campaign budget.

The delivery system seeks the highest volume opportunities first. When those lower cost opportunities run out, the system may move on to more expensive options, depending on your bid strategy. This means you may see costs increase over the schedule of your campaign.

The part that confuses people is that the ad set getting the most money can show the highest cost per result. Meta's page on reporting with the highest volume bid strategy says you "shouldn't judge" the split that way, and works through an example. Three ad sets share a $30 campaign budget. Ad set A has 4 opportunities at $5 each. B has 6 at $2. C has 3 at $1, then one at $7 and one at $8.

A has the most expensive results and gets half the money. Turn it off and the campaign buys C's $7 and $8 results instead. Split the budget evenly and A and B are each held back, while C spends its last dollars on a $7 result. Meta's explanation: "C has inexpensive initial optimization events available, but it quickly gets much more expensive to spend money on it. A has more expensive initial optimization events, but its cost per optimization event is more stable."

Meta's caveat on that example matters: "you won't have information on things like the total number of opportunities for each ad set or how much each result costs when actually running and analyzing reports on your campaigns." You see the first row, never the other two. That is why Meta's advice is to judge "the total number of results for your campaign and the average cost per optimization event at the campaign level."

How do I get my ads or ad sets to deliver equally?

Meta has no "spend equally" switch. What it offers depends on the level.

Between ads, there is no budget at all; the budget sits on the ad set or the campaign. Meta's troubleshooting page for ads not getting results: "If you want your ads to deliver equally, try creating an A/B test." Why a new ad gets almost nothing next to a proven one, and the three documented ways around it, are in Meta has no per-ad budget.

Between ad sets, there are three options on Meta's pages:

1. Ad set budgets. Each ad set spends its own budget. Meta's best-practices page says "If you have strict budget requirements for each ad set in your campaign, you may want to consider using ad set budgets instead of Advantage+ campaign budget."
2. Spend limits inside Advantage+ campaign budget: a minimum or maximum per ad set, covered next.
3. An A/B test. Meta suggests one for ads that should deliver equally, and the same tool compares ad sets.

Ad set spend limits: what minimum and maximum actually do

Meta's About ad set spend limits with Advantage+ campaign budget page says spend limits "can be set based on percentage or dollar amount", and opens with a warning: "we recommend using the least amount of spend limits, because such limits can prevent a campaign budget from taking advantage of the best opportunities available."

The two limits work very differently:

Meta's example for when a minimum makes sense: one ad set targets California, where the brand is strong, and one targets New York, where it isn't. "Without a minimum spend limit, campaign budget may spend more budget on your California ad set to get the most efficient short-term results." A minimum lets you pay to learn about the new market.

The traps, all from the same page:

• A minimum is a target, not a floor. Meta calls it "a target range, not a guarantee", though one of its examples reads as a hard floor: with a $50 campaign budget and a minimum of at least $20, "we can’t spend less than $20 on your ad set." The no-refund line sides with the target, so plan on it.
• Maximums can strand budget. With a $50 campaign budget across 5 ad sets capped at $10 each, pausing one ad set means "we'd now spend up to $40 for the week", even though the campaign budget is still $50. Raising the campaign budget without raising the caps does nothing either: "we can't use that additional $10."
• Minimums must fit the budget. "Your minimum spend limit must be the same or less than your campaign budget. Otherwise, we can't meet your minimum spend limit."
• Bid controls can make a minimum unreachable. "Using Cost per result goal bidding or bid cap can constrain delivery, potentially making minimum spend limits unachievable." The bid strategy entry covers those options.
• Not both at once. "We don't recommend adding both minimum and maximum spend limits to an ad set at the same time." If you do, Meta wants "at least a 0.9% difference between them" and "at least a difference of $1".
• Switching resets them. "If you switch from campaign budget to ad set budgets, your spend limits will be reset."
• Edits are not instant. "It takes up to 15 minutes after publishing for spend limit edits to take effect."

Using spend limits does not switch Advantage+ off. Meta's Advantage+ on and off page lists "Use optional spending limits" among the things that still show Advantage+ on.

Ad set budget sharing: the middle option

The third strategy on Meta's comparison page is ad set budget sharing, for campaigns that don't use a campaign budget. You keep a budget on each ad set, and "up to 20% of your daily budget" can move to other ad sets "depending on when more opportunities are available". Meta's page is explicit that this doesn't raise the campaign total: "At a campaign level, spend remains the same whether ad set budget sharing is on or off."

Meta's example, for two ad sets with daily budgets of $10 and $20:

Each ad set can therefore reach 210% of its daily budget on a single day; how that fits with the usual 175% daily ceiling is covered in how much Meta can overspend a daily budget. Two limits from Meta's pages: the setup page opens with "This feature may not be available to you yet", and sharing needs at least two active ad sets, "Otherwise, ad set budget sharing will not be applied because there are no active ad sets to share budgets with."

What does Meta say not to do with Advantage+ campaign budget?

Meta's Best practices for Advantage+ campaign budget page is mostly a list of things that look sensible and backfire:

• Don't pause ad sets with low delivery. "Pausing a low delivery ad set today prevents Advantage+ campaign budget from finding tomorrow's opportunities. This can ultimately cause an increase in cost per action (CPA) for your active ad sets."
• Don't pause and unpause. "Pausing an ad set removes it from consideration." With two ad sets, pausing one means the budget goes "entirely on the active ad set. By the time you unpause the other ad set and it starts to run, there might not be any budget left in the campaign."
• Add ad sets in bulk. "Whenever you add a new active ad set to your campaign, it can take about 2 hours for Advantage+ campaign budget to re-adjust."
• Make changes in bulk. "If you input changes one at a time, your campaign may have to re-enter the learning phase each time."
• Make sure every ad set can deliver. "If an ad set isn't delivering, it isn't encountering any opportunities for results, and we can't distribute budget to it."
• Keep it to 70 ad sets. "Don't exceed 70 ad sets per campaign." That is the recommendation; the hard limit is 200, below.

Does changing the campaign budget reset the learning phase?

It can, for several ad sets at once. Meta's significant edits page carries two notes for campaign budgets:

When using Advantage+ campaign budget, adjusting your campaign budget might cause multiple ad sets within the campaign to reenter the learning phase.

When using Advantage+ campaign budget … switching your campaign bid strategy might cause multiple ad sets within the campaign to reenter the learning phase.

Meta's example of scale: "$100 to $101" is not likely to reset anything, "$100 to $1000" may. The budget moving between ad sets on its own does not count: "No, ad sets within the campaign won't reenter the learning phase as budget is distributed." What does count is in the learning phase post.

What are the rules for turning it on?

From Meta's setup page, a campaign needs, across all its ad sets:

• "The same budget type for all ad sets (lifetime or daily)."
• "The same bid strategy for all ad sets (highest volume, bid cap, or cost per result goal)."
• "The same delivery optimization event for all ad sets, if the bid strategy is highest volume."
• "Standard delivery type selected for all ad sets."

Switching has a cooldown: "There's a required 2 hour minimum time limit when switching Advantage+ campaign budget on or off." Meta's workaround if you need it off sooner is to "pause the campaign and create a new one with ad set budgets."

Large campaigns lock in. Meta's page on 70+ ad sets says a campaign using Advantage+ campaign budget can hold "more than 70 ad sets (but no more than 200)", counting "active and inactive ones". Past 70, you can't "Turn off Advantage+ campaign budget" or "Edit the campaign bid strategy" after publishing; Meta's fix is to duplicate the campaign or ad set, which "may re-enter the learning phase". And a campaign above 70 ad sets that isn't using a campaign budget can't turn it on "without decreasing your ad sets."

What it means for your campaigns

1. Uneven spend across ad sets is the feature, not a fault. Judge results and cost per result at the campaign level, as Meta's results and best practices pages say.
2. If you don't value your ad sets the same, say so in the structure. Use ad set budgets, or a minimum spend limit on the one that has to be funded, knowing Meta calls the minimum a target, not a guarantee.
3. Leave low-delivery ad sets running unless they are broken. Meta says pausing them raises cost for the rest.
4. Batch your changes. New ad sets take about 2 hours to fold in; campaign budget and bid strategy changes can send several ad sets back into learning.
5. To fund new ads inside a campaign, use Meta's creative test. Its share of an existing budget is the one setting aimed below the ad set; for an even split between ad sets, run an A/B test.

Sources

• About Advantage+ campaign budget — Meta Business Help Center (accessed October 24, 2026)
• About campaign budgets and ad set budgets — Meta Business Help Center (accessed October 24, 2026)
• Understand Advantage+ campaign budget reporting when using the highest volume bid strategy — Meta Business Help Center (accessed October 24, 2026)
• Understand Advantage+ campaign budget results — Meta Business Help Center (accessed October 24, 2026)
• Troubleshoot ad delivery: Your campaign slowed down or stopped — Meta Business Help Center (accessed October 24, 2026)
• Troubleshoot ad performance: You're not receiving enough results — Meta Business Help Center (accessed October 24, 2026)
• About ad set spend limits with Advantage+ campaign budget — Meta Business Help Center (accessed October 24, 2026)
• About ad set budget sharing — Meta Business Help Center (accessed October 24, 2026)
• How to use ad set budget sharing in Meta Ads Manager — Meta Business Help Center (accessed October 24, 2026)
• Best practices for Advantage+ campaign budget — Meta Business Help Center (accessed October 24, 2026)
• Significant edits and learning phase — Meta Business Help Center (accessed October 24, 2026)
• Set up Advantage+ campaign budget — Meta Business Help Center (accessed October 24, 2026)
• About using Meta Advantage+ campaign budget for campaigns with 70+ ad sets — Meta Business Help Center (accessed October 24, 2026)
• What turns Advantage+ on and Advantage+ off — Meta Business Help Center (accessed October 24, 2026)

---

Every figure above, including the dollar examples, is Meta's own. Meta revises these pages without notice, so check the source before acting on a quote.

Terrads makes the creative for every ad set in a campaign, so the one that wins the budget has strong ads to spend it on.