Question 372: what is the kaffarah for one day of not fasting Ramadan? (besides fasting 60 days)
Answer 372: There are nine acts which invalidate fast as follows: 1) Eating and drinking. 2) Sexual intercourse. 3) Masturbation (Istimna) which means self-abuse, resulting in ejaculation. 4) Ascribing false things to Allah, the Almighty or his Prophet or to the successors of the Holy Prophet (pbuth). 5) Swallowing thick dust. 6) Immersing one’s complete head in water. 7) Remaining in Janabat or Haidh or Nifas till the Adhan for Fajr prayers. 8) Enema with liquids. 9) Vomiting.
Commission of the things which invalidate fast as mentioned earlier are a cause of expiation in the same way as they make it obligatory to compensate for it, when it is done deliberately and willingly without any coercion, according to the more cautious opinion, as regards lying about Allah, the Exalted, His Prophet, Blessing be on him and his Progeny, and the Imams, Peace be upon them, and dipping in water, and having enema, and according to the stronger opinion, in case of the rest; rather, in case of lying about them, (Peace be upon them) is also not devoid of force. Of course, according to the stronger opinion, vomiting does not make it obligatory.
According to the more cautious opinion, in this respect there is no difference between the person knowing and an ignorant person who is neglectful. As regards an incapable (or interdicted) person who fails to pay heed to make query apparently it is not obligatory on him, though it would be more cautious (in his case too).
Note: Here are three types of expiations (Kaffarah) for giving up the fast of the month of Ramadãn:
Emancipation of a slave, keeping fast for two months consecutively and feeding sixty indigent persons, whichever is chosen by him, though, it is more cautious to select one of them according to the above order, if possible. It is more cautious to perform all the three types of expiations if a person has broken his fast by something prohibited, such as eating something usurped, drinking wine, or having a prohibited sexual intercourse, or the like.
According to the stronger opinion, expiation is not repeated with the repetition of its cause in a single day, including performance of sexual intercourse, even if the type of its cause differs, but caution must not be given up in case of performance of sexual intercourse.
Conclusion: The Kaffarah of leaving out a fast of Ramadhan is to: (a) free a slave, or (b) fast for two months or (c) feed sixty poor to their fill or give one mudd (= 3/4 kg.) of food-stuff, like, wheat or barley or bread etc. to each of them. If it is not possible for him to fulfil any of these, he should give Sadaqa according to his means and seek Divine forgiveness. And the obligatory precaution is that he should give Kaffarah as and when he is capable to do so.
A person who intends fasting for two months as a Kaffarah for a fast of Ramadhan, should fast continuously for one month and one day, and it would not matter if he did not maintain continuity for completion of the remaining fasts.
As regards the payment of expiation by feeding the poor it may be done either by feeding them to their full or by giving each of them a Mudd of wheat, barley, flour, rice, bread, or any other foodstuff, though, it is more cautious to give two Mudds. It is not sufficient in a single expiation to feed a single person twice or several time times or giving him two or more Mudds, when sixty poor persons are available, rather it would be indispensable that there should be sixty poor persons. If a person has a family (of several members), it shall be permissible to give him according to one Mudd for each member, provided that there is surety that the person shall feed them or give the food to them. One Mudd is equal to a quarter Sà’, and a Sã’ is equal to 214 ¼ Mithqals.
نمایه: چیزهایی که روزه را باطل می کند / آنچه که برای روزه دار مکروه است، سوال شماره 37.
 . Tawzih al-Masael (with annotation of Imam Khomeini), Vol. 1, Pg. 931, Q 1660 & 1661; Tahrir al-Wasilah of Imam Khomeini (ra), Vol. 1, Pg. 289; The Official Website of Grand Ayatollah Sistani (ha), rules concerning things which make a Fast void, issue #1582.