Flight log / Transmission 038

Target CPA vs. Maximize Conversions: which bid strategy, and when to switch

One strategy spends the budget. The other aims at a number. In 2026 Google pulled them apart in the interface and changed how the number behaves when budget runs tight, so the old rules of thumb need a recheck.

Both strategies are Smart Bidding. Google describes Smart Bidding as bid strategies that use Google AI to "optimize for conversions or conversion value in every auction," a feature it calls auction-time bidding. Both use signals like device, location, time of day and remarketing lists. Both need conversion tracking. The difference is what they treat as the constraint.

This guide covers how each one spends, what Google changed in June and August 2026, how much conversion data you need, how to switch without wrecking a month, and where both strategies struggle in B2B.

What's the difference between Target CPA and Maximize Conversions?

Maximize conversions sets bids to get as many conversions as possible within your budget. Google's help page says it "will try to fully spend your average daily budget," and warns that a campaign spending well under budget may see spend rise noticeably after the switch. There's no cost ceiling per conversion. The budget is the only brake.

Target CPA sets bids to get as many conversions as possible at the average cost per acquisition you choose. Google is clear that it's an average: some conversions will cost more than the target and some less. If the target is too low, Google says the strategy may skip clicks that could have converted, which lowers total conversions. If the target is reachable without spending the whole budget, it may not spend the whole budget.

Isn't Target CPA part of Maximize Conversions?

It was, and the naming has moved twice, which is why so many answers online disagree.

• July 2021. Google removed the standalone Target CPA strategy for new standard Search campaigns and folded it into Maximize conversions as an optional target. Search Engine Land reported Google's statement that using Maximize conversions with a target CPA "will have the same bidding behavior as Target CPA."
• June 2026. Google started relabeling "Maximize conversions with a Target CPA" back to a standalone "Target CPA" option for Search campaigns. Google calls it "purely a visual change to the labels." During the transition the Google Ads API, Google Ads Editor and the mobile app may still show the old names.
• August 17, 2026. A real behavior change, separate from the labels. Google says budget-limited Target CPA and Target ROAS campaigns now "perform more consistently toward your bid target."

The August change matters most for this decision. Google's own example: a campaign with a $10 target CPA that was actually achieving $5 "now delivers more closely to a $10 USD actual CPA." Before, a budget-limited campaign that beat its target could sit comfortably under it. Now the target is treated as the target. Google won't adjust your targets or budgets for you, and it lists three options: keep the target, set it to match recent results, or switch to Maximize conversions, which Google describes as optimizing "to spend your full budget without a target."

Which strategy gets more conversions?

Usually Maximize conversions, because it's allowed to spend everything. The question is what those extra conversions cost. The hypothetical campaign below has a $13,000 monthly budget and a stable recent CPA around $180.

In this illustrative scenario, Maximize conversions spends the full $13,000 for 62 conversions, about $210 each. Target CPA at $180 gets 55 conversions at roughly $178 and leaves about $3,200 unspent. Target CPA at $120 is the trap: Google warns a target set too low can skip convertible clicks, and here it gets 31 conversions on less than $4,000 of spend.

Neither of the first two is wrong. The 7 extra conversions from Maximize conversions cost about $3,200, or roughly $460 each at the margin. If a qualified lead is worth more than that to you, spend it. If not, Target CPA is doing its job. That marginal math is the whole decision, and most teams only look at the blended average.

One related trap: Google says it doesn't recommend using the Lost IS (budget) column with Maximize conversions, because the strategy is "limited by budget" by design. More on reading that column in our guide to search impression share.

How much conversion data do you need?

Google doesn't publish a hard minimum for Target CPA on Search campaigns. What it does publish:

• Its About Smart Bidding page recommends measuring performance over periods "that have at least 30 conversions." It also notes Target ROAS needs 50 conversions.
• Its About Target CPA page says that with history, Google recommends a starting target equal to your average CPA over the last 30 days, adjusted for conversion delay.

The practical read: if a campaign gets a handful of conversions a month, a CPA target is mostly noise, because a single lead swings the average by a large amount. That's the common B2B case. Teams usually handle it by consolidating campaigns so conversions pool together, by giving a portfolio strategy more data, or by bidding to an earlier, higher-volume action and accepting that it's a proxy. Each option trades precision for signal. Pick deliberately.

If your conversions have very different values, CPA is the wrong lens entirely. A demo request and a newsletter signup aren't worth the same. See value-based bidding for B2B lead gen.

When should you switch from Maximize Conversions to Target CPA?

Switch when three things are true: the campaign has a steady flow of conversions, its CPA has been stable for at least a month, and you know the CPA you can afford. Before that, a target is a guess, and the strategy will hold you to it.

How to do it with the least damage:

1. Set the first target near recent actual CPA. Google's recommended target is your last 30 days of CPA. Starting much lower than reality is the most common way to choke a campaign.
2. Use an experiment if volume allows. Google's Target CPA page offers "Save as experiment" so you can compare the new setting against the original campaign rather than switching cold.
3. Remove old manual bid adjustments. Google says they can conflict with Target CPA. Note that device adjustments change the target, not the bid: a +40% mobile adjustment on a $10 target makes the mobile target $14.
4. Move the target in steps. Each setting change can put the strategy back into Learning. Small, spaced moves are easier to read than one big one.

Here's what a clean transition can look like. Both lines are indexed to the 4 weeks before the switch, so 100 is the old average.

In this hypothetical, the week of the switch is messy: CPA jumps and volume drops while the strategy recalibrates. By week 8, CPA settles about 12% below the old average and conversions about 5% below. That's the normal trade: a bit less volume for a predictable cost. If conversions had kept falling after week 7, the target would be too tight.

What happens during the learning period?

Google's bid strategy status page lists three triggers for the Learning status: the strategy was recently created or reactivated, a setting was changed, or campaigns, ad groups or keywords were added to or removed from the strategy. Google's learning period article says it can take a few conversion cycles, typically 1 to 2, for the strategy to calibrate, and that duration depends on conversion volume, conversion cycle length and the strategy itself.

Conversion cycle is the important part for B2B. If leads typically convert 10 days after the click, one cycle is 10 days, not one. Day-level CPA during learning is mostly noise, as this illustrative example shows.

In this hypothetical, daily CPA swings between $140 and $290 in the first week, then narrows toward the target. With two or three conversions a day, one extra or missing lead moves the daily number by a quarter to a third. Judge the change over full conversion cycles, not days.

Seasonality adjustments and data exclusions

Two tools exist for the moments the strategy can't see coming. Seasonality adjustments tell Smart Bidding to expect a conversion rate change. Google says they're ideal for short events of 1 to 7 days and may not work as well when used for more than 14 days at a time. They're supported for Search campaigns on Target CPA and Target ROAS, and Google says not to use them for normal seasonality because Smart Bidding already handles it. Data exclusions tell Smart Bidding to ignore dates when conversion tracking broke, so a tagging outage doesn't teach the bidder that your traffic stopped converting.

Where both strategies struggle in B2B

• The conversion isn't the outcome. Both strategies optimize to whatever you count. If a form fill counts and half of them are students and competitors, the bidder will happily buy more of those. Fix what you count before you fix how you bid.
• Delayed offline conversions. If qualified leads are uploaded weeks later, the bidder learns slowly and recent CPA looks worse than it is. Google adjusts its recommended target for conversion delay; you should adjust your reading too.
• Average target vs. entered target. Google reports an "average target CPA," the traffic-weighted target the strategy actually optimized for, which can differ from what you typed. Compare actual CPA with that, not the raw number.
• Overperforming targets got pulled up. After August 2026, a budget-limited campaign that was beating its target can now spend toward it. If CPA rose in late August and nothing else changed, check the target first.
• The page sets the ceiling. Bidding decides which auctions to enter and how much to pay. It can't make the landing page convert better. A better conversion rate lowers CPA under either strategy, which is the lever bidding can't pull for you. For the wider picture, see the B2B PPC playbook.

Target CPA or Maximize Conversions: the quick decision

1. New campaign or thin data: Maximize conversions with a budget you're comfortable spending in full.
2. Stable CPA for a month and a known affordable CPA: Target CPA, starting near recent actual CPA.
3. Budget-limited Target CPA campaign beating its target: lower the target to match results, or move to Maximize conversions if you want the full budget spent.
4. Conversions with very different values: neither; look at value-based bidding.
5. Short promotion with a big expected conversion rate change: keep the strategy and add a seasonality adjustment.

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