How many conversions does Google Ads bidding need?

What does Google itself say about minimum conversions?

For Target CPA, Google sets none and lets you start with no conversion history. For Target ROAS, Google lists a minimum per campaign type.

A manufacturer closes deals worth six figures, and most months its website form gets filled in the single digits. Can Google bid for those forms on its own?

It will. Google Ads Help on Target CPA says "Advertisers can start using Target CPA with no conversion history," and recommendations can appear for low-volume campaigns. Its one number is for checking results afterwards: "For evaluation, we recommend you measure performance for the last 30 days, including at least 30 conversions."

Google's Target ROAS help page is stricter, with a minimum per campaign type. Google began relabeling both strategies in June 2026, so we reopen both pages before changing a setting.

Where do the 15, 30, and 50 figures come from?

Google's pages give the 15 (Target ROAS) and a 30 for evaluating Target CPA. The 50 a month and the 30 a month minimum come from a vendor and an agency.

Frederick Vallaeys, co-founder and CEO of the PPC software company Optmyzr, wrote on May 28, 2026 that "our data shows the consistent threshold is around 50 conversions per 30-day period." His post on when to stop Smart Bidding covers more than 14,000 accounts and gives no method, so it is Optmyzr's number.

Ishan Manchanda's GrowthSpree post on long B2B sales cycles, from May 8, 2026, says Smart Bidding "needs 30+ conversions/month minimum to optimize." It credits Google with a 50+ recommendation, unlinked, which neither Google page says. Chris Hutty wrote in a Jellyfish post on low-conversion accounts, last updated October 22, 2024, that Google suggests "a minimum of 15 conversions a month at a campaign level." Google's current Target CPA page does not.

Why are B2B accounts hit hardest?

A closed deal, the conversion B2B companies care about most, arrives in small numbers. GrowthSpree says 5 to 15 closed-won deals a month starve Smart Bidding.

The manufacturer at the top of this page is Optmyzr's example. Vallaeys calls it the hardest case for automated bidding, with six-figure deals and form submissions "in the single digits most months." It would take months to reach the 30 conversions Google suggests for judging results.

The same post quotes one B2B advertiser, unnamed: "We don't use Google's automated bid pricing because it tends to consume money."

What can a low-volume account feed the bidder instead?

A conversion that happens more often and still tracks revenue, usually a qualified lead sent back from your CRM.

Picture a lead-gen account that counts a handful of closed-won deals a month. Switching the goal to qualified leads, the stage where sales accepts a lead, raises the count while keeping junk form fills out. GrowthSpree recommends exactly that until volume scales, and we agree.

That stage reaches Google Ads through an offline conversion import from the CRM. Jellyfish describes Enhanced Conversions for Leads as passing hashed personal information from lead forms to Google, and suggests a GA4 key event for a micro conversion when even qualified leads are scarce.

Google's Target ROAS page says performance generally improves with fewer, larger campaigns that get more conversions, so we merge small Search campaigns aimed at one buyer before giving any of them a target. Running ad budgets is a service our team at Corvan does by hand, through our ad operations service.

Should small accounts use manual bidding?

Below about 30 conversions a month it is a fair choice, and that is where GrowthSpree draws the line. Google does not require it.

GrowthSpree's table puts accounts under 30 conversions a month on Manual CPC or Maximize Clicks, with the note "Build conversion volume before automation." From 30 to 50 it moves to Maximize Conversions, still without a Target CPA. That is agency opinion with no data, and close to what we would do, though manual bids become somebody's weekly job. Our paid ads guide covers the rest of the paid side.

Nobody has shown us the gap itself. Neither Google nor Optmyzr publishes how a Target CPA campaign with single-digit monthly conversions performs against one with 50, and we have not found anyone who has.