Family name 凯丝 (Kaas 
, 凯丝 
) , all over the world, is quite a rare cognomen. The surname 凯丝 is habitual in Northern Europe, particularly Denmark, where it is quite a common surname, Estonia, and Norway, where it is quite a rare surname. Measured by absolute frequency, it is the most numerous in Denmark, Germany, and the United States. Very seldom, 凯丝 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kaas | Netherlands, France, Germany, United States, Denmark |
| 凯丝 | China |