What do you mean with undersized? My standard European bathtub is roughly 140x52 cm on the inside. That is too short. So either the knees, or the upper body s

What do you mean with undersized? My standard European bathtub is roughly 140x52 cm on the inside. That is too short. So either the knees, or the upper body stick out of the water. Not sure about the width though. What is the average width of an American? Being wider than half a meter seems unusual.