Smart Bidding in 2026: Data Thresholds and When to Switch

Smart Bidding is the set of Google Ads bid strategies that use Google AI to optimize for conversions or conversion value, with a new bid at each auction. For Search campaigns, Google names four: Maximize conversions, Maximize conversion value, Target CPA and Target ROAS.

Bidding is the last layer of a Search campaign, not the first. Below, I show which strategy to pick, how much data each needs, what resets the learning period, and how I change targets. Google's numbers link to Google's pages. My rules are marked as mine.

Smart Bidding strategies: which one to use

Check tracking and budget first. Then pick by what a conversion is: a sale with revenue points to Target ROAS; a lead or a call points to Target CPA.

The budget question is my rule. The value questions are Google's. Both numbers are in the data section below.

Maximize clicks is automated, but it is not Smart Bidding: it bids for clicks, not conversions.

How Smart Bidding works and which signals it uses

Smart Bidding sets a new bid at each auction from auction-time signals, and it bids for the conversions you mark as Primary.

Google lists device, location, time of day, remarketing list and language among the signals. Its full table adds the actual query, ad creative, browser and operating system. Google says Smart Bidding adjusts for interactions between “billions of combinations of signals.”

The signals only help if the goal is right. Smart Bidding bids for primary conversion actions. Secondary actions are “for observation only” unless they are part of a custom goal. If a button click counts as a primary conversion, Smart Bidding learns to buy button clicks. My conversion tracking guide shows how to check yours.

How much data Smart Bidding needs in 2026

Turning Smart Bidding on takes little data, but reading its results takes at least 30 conversions over a month or longer (50 for Target ROAS).

Switching a strategy on and reading its results are different questions. The Target ROAS page asks for “at least 15 conversions in the past 30 days” before you can switch it on. The Smart Bidding page suggests measuring over periods with “at least 30 conversions, such as a month or longer (50 conversions for Target ROAS).”

In the accounts I manage, the monthly budget floor for Search with Smart Bidding is CPA × 50 conversions, plus 15-20%. A $10 CPA gives $500. Add 15-20%, and you get about $600 a month. When the budget allows, I aim for 50 conversions a week, because learning goes faster. For Target ROAS, I take the cost per conversion from the last 30 days as the CPA.

The learning period in 2026: what resets it

The Learning status “never lasts more than 7 days,” and budget or target changes do not start it.

This corrects advice you still see often, including in an earlier version of this guide: that a big budget change restarts learning. Google says daily budget changes let campaigns scale “without triggering ‘Learning’ status.” Target changes do not trigger it either.

No label does not mean no effect. After a new strategy, a target change or a major budget change, Google says results need “1-2 conversion cycles” to settle. A conversion cycle is the time from a click to the conversion. For an online store, that can be a day. For B2B, it can be weeks.

Target ROAS when sales fluctuate: change targets in small steps

When sales swing for a few days, I leave the target alone. When the shift lasts, I move it 5-10% at a time and track each step for 7-20 days.

The step and the wait are my rule. Google's page for Search campaigns names no percentage, but it says to “avoid making multiple ROAS target changes within a single conversion cycle.” For cycles over 20 days, I wait one full cycle. The same Optmyzr analysis suggests staying within about 10% of past results.

Five Smart Bidding mistakes I find in audits

In my experience, these five come up most often in the 100+ accounts I have reviewed. If you would rather hand this over, see my Google Ads management service.

Smart Bidding FAQ