Tight enough that it remains in place without requiring constant readjustment, but not too tight that it feels uncomfortable and risks cutting off circulation. This issue is why it’s recommended that you carefully measure the knee area before purchasing a knee sleeve. Due to the compression features of knee sleeves, they will feel ‘tight’ as a rule, but you should have a good enough idea of what’s comfortable and what’s not in determining whether or not you purchased a knee sleeve that was too small.\r