Surname Khwachai (Khwachai 
) , in all the world, is a very rare cognomen. The last name Khwachai is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Khwachai | Thailand |
Darin, Porniwat, Ratthapong, and Wachirawat