Last name Каер (Kayer 
, Kaer 
, Каер 
) , worldwide, is quite a rare surname. The last name Каер is habitual in Estonia, where it is quite a rare surname, Denmark, and Taiwan, where it is a rare surname. In absolute terms, it is commonest in Indonesia, Turkey, and the United States. Also, Каер is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kayer | India, Bangladesh, United States, Turkey, Austria |
| Kaer | Taiwan, India, Estonia, United States, Indonesia |
| Каер | Russia, Kazakhstan, Ukraine |