Last name Dumancas (Dumancas 
) , all around the world, is quite a rare cognomen. The cognomen Dumancas is habitual in Philippines, where it is quite a rare surname, Saudi Arabia, where it is a rare surname, and Canada, where it is a very rare surname. Measured by absolute frequency, it most frequently occurs in Philippines, the United States, and Indonesia.
| VARIANT | COUNTRY |
|---|---|
| Dumancas | Canada, Saudi Arabia, Philippines, United States, Indonesia |