Cognomen Cvas (Квас 
, Cvas 
) , worldwide, is quite a rare last name. The family name Cvas is characteristic of Eastern Europe, particularly Ukraine, where it is quite a rare surname, Romania, where it is a rare surname, and Russia.
| VARIANT | COUNTRY |
|---|---|
| Квас | Kazakhstan, Russia, Kyrgyzstan, Belarus, Ukraine |
| Cvas | Romania |