How long does one have to say Birkat HaMazon?

From Halachipedia
  1. If one forgot to make Birkat HaMazon right away, one may make the Bracha as long as one is full. [1]
  2. However, if one just had a Kezayit and isn't full, one should try to make the Birkat HaMazon right away and if one didn't one may only make Birkat HaMazon up to 72 minutes after one ate. [2] Some add that if one waited more than a half hour it's preferable to have another Kezayit of bread before making Birkat HaMazon. [3]
  3. If one has a very long meal and continues to have appetizers or drinks, one may make the Birkat HaMazon as long as the meal continues even 4 or 5 hours. [4] One should have something to eat or drink every 72 minutes, however, if one didn't then one may still say Birkat HaMazon. [5]

References

  1. Yalkut Yosef (Brachot pg 300), Vezot HaBracha (chap 5, pg 49) quoting S"A 184:5
  2. Yalkut Yosef (Brachot pg 300), Mishna Brurah 184:20
  3. Vezot HaBracha (chap 5, pg 50)
  4. Mishna Brurah 184:18, Vezot HaBracha (chap 5, pg 50), Yalkut Yosef (Brachot pg 301)
  5. Vezot HaBracha (chap 5, pg 51) quoting the Magan Avraham 184:9