Short answer
Fasting becomes fard at puberty. Before that, the Hanafi school says parents should have a child fast when able, from about seven, and be firmer around ten, as with prayer. Start with half days or a few fasts and build up.
Fasting is not fard on a child. The guardian should order a child who is able to fast from about seven and be firmer at ten. A child who breaks a fast owes no make up and no kaffarah.
Other madhhabs
- Maliki
- The well-known Maliki view is that children are not ordered to fast before puberty, though letting them try is fine.
Explanation
Al-Rubayyi' bint Mu'awwidh said that after the fast of Ashura was announced, the Companions would have their young children fast and would make them toys of wool. When a child cried for food, they gave the toy to keep him busy until iftar. This shows the Companions trained children to fast before it was due.
A gentle plan:
- Age 5 to 7: a few hours, or until lunch, on weekends.
- Age 7 to 10: some full fasts, perhaps the weekends or the last ten nights, then more each year.
- Age 10 onward: most or all of Ramadan, if the child is healthy.
- Let them wake for suhoor and break the fast with the family. Praise every fast.
A child who is ill, very thin or struggling at school in long summer days should not be pushed. The goal is love of fasting, not a record.
When it becomes fard: the moment a child reaches puberty, fasting is fard. Girls often reach it at nine to twelve with their first period, so prepare them early. A child who reaches puberty partway through Ramadan fasts the remaining days and does not make up the earlier ones. See the Ramadan fasting rules and what breaks your fast.
The evidence
Quran, Surah Al-Baqara 2:185
شَهْرُ رَمَضَانَ ٱلَّذِىٓ أُنزِلَ فِيهِ ٱلْقُرْءَانُ هُدًۭى لِّلنَّاسِ وَبَيِّنَٰتٍۢ مِّنَ ٱلْهُدَىٰ وَٱلْفُرْقَانِ ۚ فَمَن شَهِدَ مِنكُمُ ٱلشَّهْرَ فَلْيَصُمْهُ ۖ وَمَن كَانَ مَرِيضًا أَوْ عَلَىٰ سَفَرٍۢ فَعِدَّةٌۭ مِّنْ أَيَّامٍ أُخَرَ ۗ يُرِيدُ ٱللَّهُ بِكُمُ ٱلْيُسْرَ وَلَا يُرِيدُ بِكُمُ ٱلْعُسْرَ وَلِتُكْمِلُوا۟ ٱلْعِدَّةَ وَلِتُكَبِّرُوا۟ ٱللَّهَ عَلَىٰ مَا هَدَىٰكُمْ وَلَعَلَّكُمْ تَشْكُرُونَ ﴿١٨٥﴾
The month of Ramadhan [is that] in which was revealed the Qur'an, a guidance for the people and clear proofs of guidance and criterion. So whoever sights [the new moon of] the month, let him fast it; and whoever is ill or on a journey - then an equal number of other days. Allah intends for you ease and does not intend for you hardship and [wants] for you to complete the period and to glorify Allah for that [to] which He has guided you; and perhaps you will be grateful.
Training should be gradual and easy, not harsh.
Sahih al-Bukhari 1960
Sahih... ونصوم صبياننا ونجعل لهم اللعبة من العهن ...
"We would make our children fast and make them toys of wool."
The Companions trained children to fast.
Jami' at-Tirmidhi 1423
Graded sahih... رفع القلم عن ثلاثة عن النائم حتى يستيقظ ...
"The pen is lifted from three: the sleeper until he wakes, the child until he grows up, and the insane until he is sane."
Fasting is not fard on a child before puberty.
Where the ruling is recorded
- al-Durr al-Mukhtar, Kitab al-Sawm, chapter on what permits breaking the fast. A child who can fast is ordered to, and disciplined for it at ten as with prayer.
- Nur al-Idah with Maraqi al-Falah, Kitab al-Sawm. On the child who reaches puberty during Ramadan.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.