Google Ads Algorithm Update: What to Optimise Before 17 August

From 17 August 2026, Google is changing how its bidding system handles campaigns that are Limited by budget and use Target CPA or Target ROAS.

The key change is simple:

Previously, some budget-limited campaigns could significantly outperform their targets. After the update, that gap may reduce.

What You Need to Do

1Identify affected campaigns

Review campaigns that are:

• Limited by budget
• Using Target CPA
• Using Target ROAS

Prioritise campaigns where actual performance is significantly better than the target currently set.

2Review Target CPA

Example:

If you leave the £50 target unchanged, Google may begin optimising closer to £50 CPA after the update.

If £30 is the level you want to maintain, consider reducing the Target CPA closer to recent actual performance.

Action: Compare Target CPA against recent sustainable CPA and adjust where required.

3Review Target ROAS

Example:

If the campaign has historically delivered 500% while the target remains 300%, performance may begin moving closer to the 300% target.

If maintaining approximately 500% ROAS is commercially important, consider increasing the Target ROAS closer to that sustainable performance level.

Action: Compare Target ROAS against recent sustainable ROAS and adjust based on profitability and business goals.

4Don't change targets just because of the update

If your existing Target CPA or Target ROAS already represents the level the business genuinely wants to achieve, leave it alone.

The objective isn't to chase historical performance. It is to make sure the target entered into Google Ads reflects the performance you actually expect the algorithm to optimise towards.

5Use Google's Bid Target Adjustment Tool

Google has introduced a Bid Target Adjustment Tool specifically for this change.

Use it to identify affected campaigns and compare current targets against recent performance before applying changes.

Treat Google's recommendation as a starting point, then validate it against:

rather than accepting recommendations automatically.

After 17 August

Once targets are aligned, budget increases should become more predictable because Google intends to maintain performance closer to the stated Target CPA or Target ROAS even as budgets change.

When scaling budgets, evaluate results over approximately 1–2 conversion cycles rather than reacting immediately to short-term fluctuations.

Simple Rule

• Actual CPA much lower than Target CPA → consider lowering Target CPA
• Actual ROAS much higher than Target ROAS → consider increasing Target ROAS
• Target already reflects the business goal → no change
• Need more volume and performance is stable → consider increasing budget after targets are aligned

The important point is that from 17 August, your bidding target needs to be intentional because Google will increasingly treat it as the performance level you actually want.