Cognomen Duplechain (Duplechain 
) , in the entire world, is a rare last name. The surname Duplechain is habitual in the United States, where it is a rare surname, New Zealand, where it is a very rare surname, and Canada, where it is an extremely rare surname. In absolute terms, it most frequently occurs in the United States, Brazil, and Canada.
| VARIANT | COUNTRY |
|---|---|
| Duplechain | United Kingdom, Canada, Brazil, New Zealand, United States |