Cognomen Siffra (Cifre 
, Cifra 
, Siffra ) , globally, is quite a common surname. The family name Siffra is habitual in Slovakia, where it is quite a rare surname, Spain, and Argentina. In absolute terms, it is the most numerous in Philippines, Spain, and Argentina. Much less frequently, Siffra is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Cifre | Spain, United States, Philippines, Argentina, France |
| Cifra | Spain, United States, Slovakia, Philippines, Argentina |
| Siffra | United States |