When it comes to size, men are classified as hares, bulls or horses. Women, on the other hand, are categorized as deer, mares or elephants. The three equal unions based on size are:

Sexual desires and carnal instincts also play a role in compatibility. A man who does not like being touched and has a low libido would be a poor match for a woman who feels intense passion while making love and enjoys being touched by her partner both during and after sex. In this case, the following categories are considered equal:

Endurance is classified as short-timed, moderate-timed and long-timed. As with the categories above, finding a partner who is your equal is important. All together, there are nine possible unions for partners according to the Kama Sutra.