Every Meta Ad Size You Need in 2026: Dimensions, Formats, and Placements (Complete Guide)

If you’ve set up a new Meta campaign recently and excluded a placement like Audience Network or Facebook Right Column, you might have noticed something different. Meta now gives you a checkbox that says: Up to 5% of your budget is spent for each excluded placement when it’s likely to improve performance. And that checkbox is turned on by default. That means when you exclude a placement, Meta doesn’t fully exclude it anymore. Not unless you go back and manually uncheck that box. Your “excluded” placement can still receive up to 5% of your ad set budget. And that 5% applies per excluded placement, not total. If you’ve excluded 4 placements, that’s potentially 20% of your budget going to places you specifically said you didn’t want. As PPC Land documented when the feature first appeared: “Campaigns with multiple placement exclusions could see significantly more than 5% of total budget directed to placements advertisers intended to avoid.” This is part of Meta’s broader push toward algorithmic control over placement delivery. They’ve been steadily removing manual controls since 2024: detailed targeting exclusions were eliminated in January 2025, Dynamic Media was enabled by default for Advantage+ Catalog ads by October 2025, and now placement exclusions have this soft override baked in. The logic from Meta’s side makes sense. Their data shows that Advantage+ Placements (where Meta chooses everything) generally delivers lower cost per result because the algorithm has maximum flexibility to find cheap impressions wherever they exist. By sneaking 5% of spend into “excluded” placements, Meta is trying to prove that those placements can contribute to your results. The problem is that many advertisers exclude placements for good reasons: brand safety concerns with Audience Network, low-quality traffic from specific surfaces, or simply because they’ve tested those placements and they don’t convert for their offer. A default opt-in that overrides those decisions without clear notice is frustrating. Let me walk you through how to actually control your placements in 2026. How Placement Control Works at the Ad Set Level At the ad set level, you have two options: Advantage+ Placements (default). Meta decides where your ads run across all 25+ placement options. You give up control, and the algorithm finds the cheapest impressions. This is what Meta recommends for most advertisers, and honestly, for purchase-optimized campaigns with strong pixel data, it often works fine. The algorithm is good at finding cost-efficient impressions. Manual Placements. You choose exactly which platforms (Facebook, Instagram, Messenger, Audience Network) and which surfaces within them (Feed, Stories, Reels, Marketplace, Search Results, etc.) your ads appear on. This gives you full control. When you select Manual Placements and deselect specific placements, this is where the 5% spending feature kicks in. After you exclude placements, look for the checkbox that allows Meta to spend limited budget on those excluded surfaces. It may appear as a recommendation or as a checked option within the placement settings. The catch: This feature currently applies to Sales and Leads campaign objectives. If you’re running Traffic, Engagement, or Awareness campaigns, the behavior may differ. Check your specific campaign setup to confirm. For campaigns where you’re testing which placements work, leaving Advantage+ Placements on makes sense. You let Meta explore, collect data, and then review the breakdown reports to see which placements actually convert. But once you have that data and know that certain placements don’t work for you, switching to Manual Placements with genuine exclusions is a reasonable choice. Just make sure the 5% override isn’t silently undermining your exclusions. How Placement Control Works at the Account Level Meta also offers account-level placement controls. These apply to every campaign in the account, so you don’t need to remember to exclude specific placements each time you create a new campaign. To access account-level placement controls: Go to Advertising Settings in your Meta Ads Manager Select Placement Controls Toggle on “My business can only advertise on specific placements“ From here, you can exclude: Audience Network (ads on third-party apps and websites) Facebook Marketplace Facebook Right Column These account-level controls are separate from the ad set level placement selections. When you set an exclusion at the account level, it overrides any ad set level settings. Even if someone on your team creates a new campaign with Advantage+ Placements, the account-level exclusion will still apply. This is the cleanest way to permanently block a placement across your account. No checkboxes to worry about. No 5% overrides. The placement is simply off. However, if you want to exclude any specific placement like for example “Ads on Facebook Reels”, then you have to do this at the ad set placement control settings. When to use account-level exclusions: You’ve tested Audience Network extensively and it consistently delivers low-quality traffic for your business Your brand has content adjacency requirements that Audience Network can’t satisfy You have compliance or regulatory reasons that require restricting where your ads appear You want a “set it and forget it” solution that applies to all current and future campaigns Important: Account-level placement controls are only available for Auction campaigns. If you are running Reach and Frequency campaigns, then you need to manage your placement selection under your ad set placement control settings. Steps to Completely Remove a Placement If your goal is to fully block a placement with zero spend leaking through, here’s the process. Option A: Account-Level Block (Recommended for Permanent Exclusions) Open Meta Ads Manager Go to Advertising Settings (gear icon > Advertising Settings) Click Placement Controls Toggle on “My business can only advertise on specific placements“ Uncheck the placements you want to block (Audience Network, Marketplace, Right Column) Click Review Changes and then Apply Wait up to 48 hours for changes to take effect across existing campaigns This is the safest method to get rid of Audience Network, Marketplace, Right Column. It applies to everything in the account and isn’t affected by the 5% spend checkbox at the ad set level. For additional placements, consider option B. Option B: Ad Set Level Block (For Per-Campaign Control) Create or edit your campaign At the ad set level, scroll to Placements Click on Show more settings to make Placement controls visible. Click and expand Placement controls Uncheck the placements you want to exclude. Look for a checkbox saying “Allow limited spending to excluded placements“. This is the option that allows Meta to spend up to 5% on excluded placements and will appear only after excluding placements. Uncheck this box. Save and publish If you don’t uncheck the box on step 6, your “excluded” placements will still receive up to 5% of your ad set budget each. Option C: Combine Both for Maximum Protection Use account-level controls to permanently block placements you never want (like Audience Network), and use ad set level controls for per-campaign adjustments (like excluding Stories for a campaign that doesn’t have vertical creative). How TheOptimizer Handles Placement Optimization Automatically Here’s the approach I recommend for experienced buyers who want the best of both worlds: algorithmic flexibility for discovery, automated protection against waste. Instead of manually excluding placements upfront (which limits Meta’s ability to find cheap impressions), start with Advantage+ Placements or a broad manual placement selection. Let Meta explore. Then use automation rules to cut underperforming placements based on actual data. TheOptimizer connects to Meta’s API and lets you build rules that automatically block placements based on performance thresholds. Here’s what that looks like: Rule: Block Underperforming Placements IF Placement Spend > $X AND Placement CPA > Target CPA by 30% AND Placement Conversions < Y THEN Block Placement Run every 10 to 30 minutes This rule gives every placement a fair chance to prove itself. If a placement spends meaningful budget and doesn’t convert at an acceptable rate, it gets blocked automatically. No manual checking. No forgetting to review placement breakdowns. Why this is better than pre-excluding placements? You don’t miss hidden winners. Sometimes a placement you’d normally exclude turns out to work well for a specific creative or audience. Automated rules let it run until the data says otherwise. You respond to real data, not assumptions. Excluding Audience Network because “everyone says it’s bad” ignores the fact that for some offers and verticals, it converts at a very low CPC. Let the data decide. You handle the 5% problem automatically. Even if Meta’s 5% override sneaks spend into an excluded placement, your automation rules will catch it if that spend doesn’t convert. The placement gets blocked based […]

Before getting into budget sharing, let’s make sure the foundation is clear. Meta gives you two places to set your budget: at the campaign level or at the ad set level. Campaign Budget (CBO / Advantage+ Campaign Budget): You set one budget for the entire campaign. Meta distributes that budget across your ad sets automatically based on where it predicts the best results. This means Meta might put 70% of your budget into one ad set and 10% into another if it believes that’s where the conversions are. You give up control over per-ad-set spend in exchange for Meta’s optimization. Ad Set Budget (ABO): You set a separate budget for each ad set. Each one gets its own fixed daily amount. If Ad Set A gets $100/day and Ad Set B gets $100/day, that’s what they’ll spend (roughly), regardless of which one is performing better. CBO is good when you want Meta to chase performance across ad sets. ABO is good when you want controlled testing with equal spend per audience or creative. Use campaign budget when you have multiple ad sets and want Meta to push more spend toward the stronger one. Use ad set budget when you want stricter control, cleaner tests, or you need to protect spend across audiences. The problem with ABO has always been that it’s rigid. One ad set might be performing well and hitting its budget cap by 2 PM, while another is barely spending and delivering weak results. Your budget is locked on both sides. The strong ad set can’t spend more, and the weak one keeps spending its allocation anyway. Ad set budget sharing is Meta’s attempt to fix that rigidity without going full CBO. What Is Ad Set Budget Sharing? Ad set budget sharing is a feature that lets Meta redistribute up to 20% of one ad set’s daily budget to another ad set within the same campaign when it predicts better performance. According to Meta’s documentation: “We’ll share up to 20% of your ad set budget with other ad sets within this campaign when it’s likely to improve performance.” Here’s how it works in practice. Say you have two ad sets in a campaign, each with a $100/day budget: Without budget sharing: Each ad set spends up to $100. Total possible spend: $200. With budget sharing: If Meta believes Ad Set A has better opportunities, it can take up to $20 from Ad Set B’s budget and shift it to Ad Set A. Ad Set A now has up to $120. Ad Set B has $80. Total campaign spend stays the same. It’s a middle ground. You still set individual ad set budgets (unlike CBO where Meta controls everything), but you give the algorithm a little room to shift money toward what’s working. LeadEnforce’s analysis describes it well: “Budget sharing allows Meta to move up to 20% of one ad set’s daily budget into another active ad set inside the same campaign. The total campaign spend does not increase. Meta simply redistributes part of the budget toward stronger opportunities in real time.” This relates directly to the campaign structure decisions we covered in our campaign structure best practices guide. If you’re running ABO for creative testing, budget sharing adds a layer of flexibility that can improve your results without giving up the control that makes ABO useful for testing in the first place. When Is Budget Sharing Active (and When to Keep It On) Budget sharing appears as a checkbox when you’re using ad set budgets with two or more ad sets. In some accounts, it’s checked by default on new campaigns. In others, it’s opt-in. Check your ad set settings to confirm. Keep it on when: You’re running multiple ad sets that target similar or overlapping audiences and you want Meta to lean into whichever one is performing better on a given day. You’re in a scaling phase and want slightly more algorithmic flexibility without fully switching to CBO. You’re running broad targeting with diverse creatives across ad sets and want the budget to follow performance. Think of it as ABO with a soft CBO layer on top. You still control the base budget per ad set. But Meta gets permission to move up to 20% around based on real-time performance signals. For campaigns where you want the algorithm to have room to optimize but you’re not ready to give up ad set level budget control entirely, budget sharing is a solid option. How and When to Disable Ad Set Budget Sharing Disabling is simple. Go to your campaign settings, find the budget sharing checkbox, and uncheck it. When to turn it off: During controlled A/B tests. If you’re testing two audiences or two creative sets against each other, you need equal spend per ad set. Budget sharing breaks that controlled environment by shifting money toward whichever ad set shows early signals, which can skew your test results before you have enough data. When testing bidding strategies. If you’re comparing cost cap vs. bid cap across ad sets (which we covered in our bidding strategies article), budget sharing can muddy the results. One ad set getting 20% more budget than the other makes it hard to attribute performance differences to the bidding strategy alone. When you have very different audience sizes across ad sets. If Ad Set A targets a broad audience and Ad Set B targets a small retargeting list, budget sharing might drain the retargeting budget toward the broader audience since it has more opportunities. That’s not necessarily better. Your retargeting audience might have higher conversion quality even if it can’t absorb more spend. When you’re running TheOptimizer’s automation rules on per-ad-set budgets. If you’ve set up automation rules that adjust budgets based on ad set performance (for example, increasing budget by 20% when ROI is stable), budget sharing might affect the total spend of the ad set. The rule changes the budget based on the ad set’s performance, but in the meantime Meta is silently shifting 20% to or from that ad set. The two systems can work against each other. For campaigns managed through TheOptimizer, I generally recommend disabling budget sharing and letting the automation rules handle budget allocation instead. TheOptimizer’s rules run every 10 minutes with explicit logic you’ve defined, whereas budget sharing operates on Meta’s internal predictions with no transparency into why it shifted the money. The Impact on Campaign Spend This is the part most people miss. Budget sharing doesn’t just move money between ad sets. It can also affect how much you spend on a given day. Segwise’s budget analysis found a critical detail: “If you have turned on ad set budget sharing, you may spend up to 75% over the total of your daily budget plus the maximum shared budget per day.” That’s worth reading twice. Without budget sharing, Meta can already spend up to 25% over your daily ad set budget on high-opportunity days (a $100 budget might hit $125). With budget sharing enabled, that overspend cap increases to 75%. So a $100 daily budget with sharing enabled could theoretically hit $175 on a strong day. Meta balances this over a 7-day window. Your weekly spend won’t exceed 7x your daily budget. But the day-to-day fluctuations can be more extreme with sharing turned on. What this means for budget planning: If you set ad set budgets with the expectation that each one will spend roughly its daily amount, budget sharing can introduce surprises. One ad set might spend 40% over its budget on a Tuesday while another spends 30% under. Over the week, it evens out, but on a daily basis the numbers look volatile. For advertisers who need predictable daily spend (client-managed accounts with fixed daily caps, or campaigns where overspend triggers compliance issues), this matters. Turn sharing off and accept the trade-off of slightly less algorithmic flexibility. Control your budgets with precision! TheOptimizer lets you build budget rules that run every 10 minutes across all your Meta ad accounts. Scale winners, protect losers, and maintain the spend control that budget sharing can undermine.   Get Started for Free FAQ Is ad set budget sharing the same as Campaign Budget Optimization (CBO)? No. CBO gives Meta full control over budget distribution across ad sets. Budget sharing still lets you set individual ad set budgets but allows Meta to move up to 20% between them. CBO can put […]

Before talking about bidding strategies, you need to understand what you’re actually bidding in. Every time there’s an opportunity to show an ad to someone, Meta runs an auction. Your ad competes against every other eligible ad targeting that same person. But the winner isn’t simply the highest bidder. Meta calculates a Total Value Score for each ad: Total Value = (Your Bid x Estimated Action Rate) + Ad Quality + User Value Three things matter. Your bid (how much you’re willing to pay). The estimated action rate (how likely this specific person is to take the action you’re optimizing for). And ad quality (how relevant and engaging your creative is based on past signals). This means a lower bid with a highly relevant ad can beat a higher bid with a poor one. Your creative quality and relevance score are multipliers on your bid. A $20 bid with strong relevance can outperform a $40 bid with weak relevance. Your bidding strategy controls one piece of this equation: how Meta decides what to bid on your behalf. Everything else (creative quality, audience relevance) is determined by your ads and your account history. The 5 Bidding Strategies Available in 2026 Meta offers five bidding strategies in 2026. Three are goal-based (they control cost), and two are spend-based (they control volume). 1. Highest Volume (formerly Lowest Cost) What it does: Meta bids whatever it takes to get you the most results within your budget. No cost control. No cap. It just spends your budget as efficiently as it can. The upside: Maximum delivery. Fastest exit from the learning phase. Zero setup. It’s Meta’s default for a reason. The downside: Your CPA fluctuates. Monday might be $25, Tuesday $55, Wednesday $30. You have no cap, so when competition spikes (holidays, weekends, industry events), your costs spike with it. Meta doesn’t care about your profit margins. It cares about spending your budget. Best for: New campaigns, new accounts, data collection phases, and situations where volume matters more than per-unit cost. 2. Highest Value What it does: Instead of maximizing the number of conversions, Meta maximizes the total conversion value. It finds people likely to make bigger purchases rather than more purchases. The upside: Higher average order value. Better for e-commerce with a wide product price range. The downside: Requires purchase value data sent through your pixel or Conversions API. Without it, Meta has nothing to optimize against. Best for: E-commerce stores where order values vary significantly ($20 t-shirt vs. $200 jacket). Useless for lead gen or flat-value conversions. 3. Cost Cap What it does: You set a target CPA, and Meta tries to keep your average cost per result at or below that target. Key word: average. Individual conversions might cost more or less, but the average should hover around your cap. The upside: Predictable costs over time. Meta still has flexibility to bid above your cap when it finds high-probability users, as long as the average stays in line. The downside: During the learning phase, costs can exceed your cap significantly before stabilizing. A lot of people burn their hands at cost caps because they expect it to behave like bid caps. Cost cap is an average, not a ceiling. Best for: Scaling campaigns where you want to maintain profitability without micromanaging bids. Ideal when you know your target CPA but want Meta to have room to find volume. 4. Bid Cap What it does: You set the maximum amount Meta can bid in any single auction. If winning an impression would require bidding above your cap, Meta doesn’t bid. Period. The upside: Hard cost control. Your CPA will never exceed your cap (on a per-auction basis). As Mathias Schrøder told Ads Uploader: “Last year was our most profitable year ever. We made a deliberate shift to prioritize profit over revenue. Bid caps were central to that strategy.” The downside: Your spend becomes the variable instead of your CPA. Some days you’ll only spend $200 of a $500 budget because Meta couldn’t find enough auctions to win at your price. Delivery can stall completely if your cap is too low. Best for: Advertisers who know their exact break-even CPA and prioritize profitability over volume. Requires data and experience. 5. Minimum ROAS (Return on Ad Spend) What it does: You set a minimum ROAS threshold (say, 2.5x), and Meta only bids on auctions where it predicts the purchase will meet or exceed that return. The upside: Directly ties bidding to revenue outcomes, not just cost. The downside: Needs high purchase volume for the algorithm to predict accurately. Not available for non-purchase optimization events. Best for: E-commerce brands with strong purchase data who want to guarantee a minimum return threshold. Cost Cap vs. Bid Cap: The Real Differences This is the comparison most people get wrong, so let me be very specific about what’s different. Cost Cap Bid Cap What it controls Average CPA across all conversions Maximum bid per individual auction Can individual conversions exceed the cap? Yes. Some will be above, some below. The average is the target. No. Meta will not bid above your cap in any single auction. What varies? Individual conversion costs fluctuate Daily spend fluctuates Daily budget usage Tends to spend your full daily budget May not spend your full budget if it can’t find enough auctions at your price Learning phase behavior May overshoot the cap initially, then stabilize May severely limit delivery initially if the cap is too tight Volume vs. profitability Leans toward volume with cost guardrails Leans toward profitability with volume trade-offs When it works best You want to scale while keeping CPA roughly predictable You want hard cost control on every conversion The fundamental mental model: With cost cap, you’re telling Meta: “Spend my budget, but try to keep the average cost around $X.” With bid cap, you’re telling Meta: “Only compete in auctions where you can win for $X or less. If you can’t find enough of those, spend less.” The trade-off is always volume vs. control. Cost cap gives you more volume with less precise control. Bid cap gives you more control with less predictable volume. When to Use Each Bidding Strategy Here’s the practical decision framework I use: Phase 1: Discovery (new campaign, new offer, new account) Use Highest Volume. You don’t know your CPA yet. You don’t know which creatives work. You need data fast. Let Meta spend freely and collect baseline numbers. Stay here for 7 to 14 days or until you have at least 50 conversions. Phase 2: Optimization (you know your numbers) Switch to Cost Cap. You now have a baseline CPA and you want to maintain it while scaling. Set your cost cap at your target CPA (not your break-even, your target). This gives Meta flexibility to find more volume while keeping your average cost in check. If your CPA starts creeping above target despite the cost cap, it usually means competition is rising or your creatives are fatiguing. See our article on detecting creative fatigue early for the specific automation rules to catch this. Phase 3: Profitability (you want to protect margins) Switch to Bid Cap. You know exactly what a customer is worth and what you can afford to pay. Set the cap at your maximum acceptable CPA with a 10 to 20% buffer for auction competition. Accept that you’ll spend less budget but at better unit economics. Phase 4: Value optimization (e-commerce with varied AOV) Layer in Minimum ROAS or Highest Value. These only make sense when you have strong purchase value data and want to optimize for revenue, not just conversion count. The transition principle: You don’t pick a strategy and stick with it forever. You graduate from one to the next as your data matures. As Stackmatix’s analysis found: “You switch strategies based on performance signals, not a calendar.” This phased approach aligns with the campaign lifecycle framework in our Meta Ads automation playbook: launch with broad settings, validate with data, then tighten controls as you scale. Can I Use Cost Cap or Bid Cap on a Brand New Account? Short answer: you can, but you probably shouldn’t. Cost cap and bid cap both rely on Meta having enough data to predict conversion probabilities. On a brand new account with zero conversion history, Meta is guessing. And guessing with a bid cap usually means one of two things: Your cap is […]