Geofences have no minimum size. Their maximum size depends on use case:

• Target Geofences have no maximum size unless Geo-Lift reporting is used. If you plan to use Geo-Lift reporting, your target Geofence cannot exceed 25 square miles.
• For example, if you use a square, it can be five miles by five miles or smaller. If you use a different shape, the platform estimates a square based on the longest side. 
• If the area is larger than 25 square miles, the Geofence is considered too large for Geo-Lift reporting.

Conversion Zones have a maximum size of 1 square mile. 

Our platform lets you draw a custom polygon fence of up to 13 points (sides).

• Small venues: Outline a single booth, retail storefront, or individual building with just a few clicks.
• Large venues: Trace the full convention center, stadium, or outdoor festival area—13 well-placed points are usually enough to hug the perimeter accurately.
• Need more coverage? Create multiple polygons or add a simple radius fence to capture overflow areas such as parking lots.

Thirteen sides strikes the right balance between precision (tight fit around real-world shapes) and real-time ad-delivery speed, so your campaigns stay fast and efficient while still targeting exactly where attendees are located.