Google has given marketers a simple but consequential control: you can now set exact lookback windows for conversion attribution in Google Analytics and have those settings flow into linked Google Ads accounts. That matters because attribution windows determine which post‑ad events get credited — and credit shifts change conversion counts, cost per conversion and automated bidding signals.

What changed

Two conversion types now accept custom integer lookback values instead of fixed or preset options:

  • Engaged‑view conversions (EVC): any integer from 1 to 30 days (previously fixed at 3 days).
  • Click‑through conversions (CTC): any integer from 1 to 90 days (previously limited to 1, 7, 14, 30, 60 or 90 days).

Find the settings in Google Analytics at Advertising > Conversion management > Settings. The same controls are exposed in the linked Google Ads conversion management interface.

Why this matters for measurement and bidding

Attribution lookback windows decide which interactions are eligible to be counted as conversions after an ad exposure or click. Allowing any integer value makes it easier to align attribution with your actual sales cycles — from fast consumer signups to multiweek B2B purchase processes.

That alignment has operational consequences. Changing a window can:

  • Shift which clicks or engaged views receive credit, altering reported conversion volume.
  • Change cost‑per‑conversion and return‑on‑ad‑spend metrics used by stakeholders and dashboards.
  • Impact automated bidding and optimization in Google Ads if those strategies use the adjusted conversions as inputs.

Practical next steps for measurement teams

  • Map conversion latency. Use transaction logs, CRM timestamps or historical analytics to establish typical conversion delays for each conversion action.
  • Choose windows that reflect business reality. Match short windows to actions that convert quickly and longer windows to slower purchase journeys.
  • Document every change. Record the date, the previous setting and the reason for the update so you can attribute metric shifts correctly.
  • Test and compare. Implement changes in a controlled period and compare conversion counts, CPA and ROAS before and after to understand the effect.
  • Align across tools. Make sure other reporting systems, attribution tools and Google Ads use consistent conversion definitions and windows to avoid mismatched signals.
  • Consider downstream noise. Longer windows can increase attributed conversions but may include late, lower‑quality actions; shorter windows tighten attribution but risk undercounting slow buyers.

For many teams this update is a straightforward way to make attribution reflect buyer behavior more accurately. For teams using automated bidding or cross‑tool reporting, the change requires governance: inconsistent windows across systems will produce conflicting performance signals.

What to watch next

After you update a lookback window, monitor conversion volume, CPA and bid outcomes over at least one full sales cycle for that action. If you use smart bidding, expect performance to change as the model retrains on the new crediting; coordinate updates with stakeholders and consider pausing aggressive automated adjustments until you validate the new signal.

Ultimately, the control makes attribution timing a configurable part of measurement strategy instead of a fixed platform constraint. Use it deliberately.