Template size varies depending on number of recognizable features in fingerprint image. Larger fingerprints have larger templates. Average IDKit template size is under 2KB. This applies to fingerprint images from standard fingerprint readers. Template size is the same for all versions of IDKit. Absolute maximum of single finger IDKit template is 4kb (this maximum is reached very exceptionally)..
It is possible to set IDKit's CFG_MAX_TEMPLATE_SIZE parameter in order to limit template size extracted from fingerprint image in IDKit.
ANSI/ISO SDK has maximum template size of 1568 bytes for ISO/IEC 1974-2 template and 1566 bytes for ANSI/INCITS 378 template (these are maximum sizes as defined by standard). Some of our customers make use of ANSI/ISO SDK when they need to fit templates in 2D bar code or other limited storage.