When building audiences in Google Analytics, ensuring they are large enough to be served in your Google Ads campaigns is essential for successful remarketing. With the Google Ads list size estimates feature, Google Analytics provides real-time estimates of your audience's eligibility across Google Ads networks at the exact time of creation. This helps you optimize your targeting criteria and avoid creating audiences that are too small to serve.
This article explains how these predictions are calculated, how to understand the status indicators, and how to troubleshoot and optimize your list sizes to ensure they meet minimum serving thresholds.
On this page
- Measurement size vs. Google Ads size
- How it works
- Understanding the status indicators
- Eligibility and requirements
- Understanding "No Prediction" messages
- How to maximize your advertising list sizes
Measurement size vs. Google Ads size
It is a common point of confusion that audience list sizes do not match between Google Analytics and Google Ads. It is important to distinguish between these two metrics:
- Measurement size (Google Analytics): This reflects the total number of users who have met your audience criteria on your website or app. This size is used purely for reporting and analytical purposes within Google Analytics reports.
- Google Ads estimated size (Advertising): This represents the portion of your Google Analytics audience that is actually eligible for remarketing on Google Ads. A user who is part of your Google Analytics audience might not be remarketable due to privacy consent choices, cookie availability, browser limitations, or lack of Google identifier matches.
Because of these factors, your Google Analytics reporting user counts are not expected to perfectly match your audience list sizes in integrated Ads products.
Note: The Google Ads list size represents only the "remarketable" portion of your Analytics audience. This is highly dependent on consent, cookie availability, and active identifier matching.
How it works
Google Analytics uses advanced machine learning models to forecast your audience's remarketing list size 30 days ahead from today.
These estimates are shown as an estimated range representing a 60% confidence interval. This means there is a 60% chance the actual list size will land within the predicted range after 30 days of list accumulation (mathematically, this represents the 20th and 80th percentile of expected outcomes).
Real-time estimates are provided for four key Google Ads remarketing channels:
- Search: Estimates for Google Search campaigns.
- YouTube: Estimates for YouTube and video remarketing.
- Display: Estimates for Google Display Network campaigns.
- Gmail: Estimates for Gmail ads.
Understanding the status indicators
To give you quick, actionable feedback during audience creation, Google Analytics uses color-coded status indicators based on the probability that your audience will meet the minimum list size requirements to serve in Google Ads.
| Color indicator | Status | What it means | Probability of being too small |
| Green indicator |
Likely large enough to serve |
The audience is highly expected to meet the minimum size threshold to serve on the selected network in 30 days. |
Low (less than 8%) |
| Yellow indicator |
May be too small to serve |
There is a moderate risk that this audience will not gather enough users to serve. Consider widening your audience criteria or increasing membership duration. |
Moderate (8% to 20%) |
| Red indicator |
Likely too small to serve | The audience has a high probability of falling below the eligibility threshold. It is highly recommended to modify the audience parameters. |
High (greater than 20%) |
Minimum requirements to serve: Today, Google Ads requires a minimum of 100 active users in the last 30 days, and a minimum of 100 active users for Display, YouTube, and Gmail networks.
Eligibility and requirements
To view Google Ads list size estimates in the audience builder, your Google Analytics property must meet the following criteria:
- Linked Google Ads account: Your Google Analytics property must be linked to at least one active Google Ads account.
- Ads Personalization enabled: Ads personalization must be turned on for the linked Google Ads account. If personalization is disabled, audiences cannot be exported and estimates will not display.
- Sufficient property traffic: The underlying advertising list size prediction models require a baseline of data to generate accurate forecasts.
Understanding "No Prediction" messages
If list size estimates do not display, the audience builder will show a "No prediction" message accompanied by one of the following reasons:
- No Google Ads link: The property is not connected to a Google Ads account.
- Predictions not yet ready: Your Google Analytics property is newly linked or has recently enabled the required features, and the system is still calibrating the predictive model.
- Low prediction confidence: The data collected from your property contains too much variance, or the segment criteria are highly unique, making it impossible to produce a reliable forecast range.
How to maximize your advertising list sizes
If your estimates are low or showing as "Likely Too Small to Serve" (Red), you can take several actions to optimize and grow your list sizes:
- Widen audience conditions: Avoid overly restrictive filter combinations. If your segment requires several
ANDconditions, consider relaxing some or usingORconditions to capture a broader subset of users. - Increase membership duration: Extend the membership duration (up to 540 days) to allow users to remain on your remarketing list for a longer period.
- Implement User-Provided Data (UPD): Set up first-party user-provided data collection (such as hashed email addresses) to improve matching accuracy and boost list sizes across networks, especially in privacy-restricted browser environments.
- Ensure proper implementation of consent mode: Ensure that your tags are correctly configured to gather the necessary user consent signals (such as ad_personalization). Respecting and accurately collecting consent choices helps Google Analytics correctly identify remarketable traffic.