What Google says
In Google's own words: “When you select the Target CPA (cost-per-action) bid strategy, you set your desired average cost per conversion.” (Google help center)
How Target CPA works
You give Google a target cost per conversion, and its Smart Bidding raises or lowers your bid in each auction to average out at that cost. It is optimizing toward a goal, not enforcing a ceiling on any single click.
The too-low trap
Set the target below what your real buyers cost and Google does exactly what you asked: it finds the cheapest conversions available, usually low-intent, then stalls once that cheap traffic runs out. Higher-value buyers sit above the ceiling, so the algorithm never bids for them. Google's own Target CPA help page warns that a target set too low "may cause you to forgo clicks that could result in conversions," resulting in fewer total conversions. The fix is to raise it, or switch to Maximize Conversion Value and feed real values so it optimizes for worth, not volume. Full breakdown in A low target CPA isn't saving you money. It is one of Google's Smart Bidding strategies, so changing the target is a bid strategy setting change and puts the campaign back into the learning period. If you do not yet have the volume to set that number honestly, Maximize conversions asks for no target at all.
The August 2026 change for budget-limited campaigns
Since August 17, 2026, Google bids target-based campaigns that are limited by budget more consistently toward the stated target, even when budgets change. If your target is $80 but you have been getting $50, the campaign now delivers closer to $80. Google will not move the target for you, so set it to the CPA you actually want.
A worked example
Say a budget-limited Search campaign spends $3,000 a month, has a Target CPA of $80, and has actually been delivering 60 conversions at a $50 CPA. Since Google's August 17, 2026 update, it bids closer to the $80 you asked for, so at the same $3,000 it trends toward roughly 37 conversions ($3,000 / $80 = 37.5). If $50 is the cost you want, lower the target to $50. Illustrative numbers, not a client result.
Common questions
What is Target CPA in Google Ads?
Target CPA (tCPA) is a Smart Bidding strategy where you set the average cost per conversion you want, and Google automatically adjusts bids to hit that average. It optimizes toward the target rather than capping the cost of any individual click.
Why is a low target CPA a problem?
A target set too low tells Google to chase only the cheapest conversions, which are usually low-intent. Performance looks good briefly, then stalls, and higher-value buyers above the ceiling are never pursued. Raise the target or optimize to conversion value instead.
What does "Limited" mean on a Target CPA bid strategy?
Google shows a Limited status when something caps the strategy: available search volume (inventory), your min or max bid limits, a budget that keeps keywords Limited by budget, or a bidding strategy Google thinks should be fully automated. Hover over the status to see which one applies.
How do you calculate a starting target CPA?
Divide spend by conversions over a recent period: $3,000 for 60 conversions is a $50 CPA. Google's recommended target is the average CPA from the last 30 days, adjusted for conversion delays, and it suggests evaluating performance over at least 30 conversions.
What changed for Target CPA on August 17, 2026?
Budget-limited campaigns on Target CPA now bid more consistently toward the stated target, so one that was beating its target drifts up toward it. Google will not change the target for you: lower it to your recent actual CPA in the Bid Target Adjustment Tool if you want to keep that performance.