I am a 5'10" male and I use the Average size pillow. I sleep on a Tempurpedic mattress, so I opted for one size smaller then the measurements suggest because of how much i sink down in to the mattress. The pillow has honestly changed my life! I used to always wake up with a sore neck and upper back, but since I started using this pillow, I wake feeling great. I know I sound like a commercial, but it really has made a difference!