My reiki sessions last from 30-90 mins.  The time length is similar to getting a massage. 90 mins is going to be more in-depth and will address a larger healing goal in one session than the 60 min or 30 min sessions. 30 mins may be all that some people need to address their desired goals in a session- especially if they just need a quick tune-up, or if they want to give reiki a try for the first time.