How Long After Eating Can One Recite Birkat Hamazon?

Greetings,

One who has eaten and is satisfied can recite Birkat Hamazon as long as he is still full from his meal, up to six hours. However, one who has eaten only a k'zait, less than a full satisfaction, can recite it only up to 72 minutes.

Sources: See Shulchan Aruch Orach Chaim (Siman 195, Section 5) and Mishna Berura (Sif Katan 6) and Halacha Brura (there Section 13, and Biur Halacha Note 11).

Blessings,

Hillel Meirs