A system and method estimates video coding complexity of a source video for adaptively transcoding the source video. A video coding complexity engine of the system is configured to receive the source video in its native format and to encode the source video into an intermediate video format. The video coding complexity engine computes a video coding complexity score for the source video. The coding complexity score can be used by an adaptive bitrate transcoding sub-system and/or an adaptive resolution transcoding sub-system for transcoding the source video.