Skip to main content

Klein Sexual Orientation Grid

Photograph of Fritz Klein

Psychiatrist Fritz Klein was a respected researcher, author of "The Bisexual Option" and editor of the Journal of Bisexuality. He invented the Klein Sexual Orientation Grid (KSOG) in 1980.

Klein's Sexual Orientation Grid was developed "in an attempt to better ... understand the complexities of human sexual attitudes, emotions and behaviours". Klein thought that Kinsey's original scale was useful to a degree, but he was concerned that there is far more to sexual identity than just who one has sex with. He also added the dimension of time to acknowledge that one's sexual identity can change.

Klein's representation still has its flaws: it doesn't recognise a bisexual identity or a bisexual community, assuming that bisexuals have a mixed gay/straight identity and associate with gay and straight people equally. It relies on the gender binary of male and female, which can cause confusion for anyone who has recently transitioned to the opposite sex (or doesn't self-identify with either sex).

What the Klein Sexual Orientation Grid does well is to open our minds to abandon easy definitions of our sexual identity and, instead, to think of our sexual identity as being multi-faceted. It can be thought of as a starter to greater awareness of sexuality. Many people have suggested additional dimensions to the Grid.

Share your feedback on this page ∇

Please provide feedback on our website. Try to include any constructive suggestions for improvements and we will do our best to incorporate them.

Back to top


Whilst every effort has been made to ensure the accuracy of the information provided in this directory, we do not accept any responsibility or liability for any errors that have occurred. It is recommended that you always check with providers that their service or organisation meets your requirements. We offer an impartial service and we cannot recommend or endorse any providers listed.

Further information