Systems and methods for deactivating an Electronic Article Surveillance ("EAS") security tag coupled to an item. The methods comprise: detecting a presence of the EAS security tag in proximity to a tag deactivator; determining a distance between the item and at least one deactivation coil of the tag deactivator, in response to a detection of the EAS security tag; dynamically adjusting a deactivation field strength setting of the tag deactivator based on the distance that was previously determined; and using the at least one deactivation coil to generate a deactivation field in accordance with the deactivation field strength setting which was previously dynamically adjusted.