Short answer
Cutting nails is part of the fitrah (natural way) and should be done at least every 40 days, ideally weekly, with Friday preferred in the Hanafi texts. No authentic hadith fixes an order of fingers, but the Hanafi books recommend starting with the right hand in a set order. You may cut nails at night, and it is good to bury the clippings.
Cutting the nails is sunnah, Friday is preferred, and leaving them beyond 40 days is makruh. Al-Durr al-Mukhtar recommends an order beginning with the right index finger. Disposing of clippings in a toilet or dirty place is disliked, and burying them is recommended.
The four schools agree on this.
Explanation
The Prophet ﷺ named cutting the nails among the five practices of the fitrah, and the Companions were told not to leave it more than 40 nights. He also loved to start with the right in his grooming and purification, so the scholars recommend beginning with the right hand. The four schools agree that it is sunnah.
The order in the Hanafi books. There is no authentic hadith that fixes the order, so treat this as good practice, not a duty. Al-Durr al-Mukhtar mentions:
- Right hand: start with the index finger and go to the little finger.
- Left hand: start with the little finger and go to the thumb.
- Finish with the right thumb.
- Feet: start with the little toe of the right foot and go across to the little toe of the left foot.
Common questions. Cutting nails at night is fine; the idea that it brings bad luck has no basis. Any day is fine, though Friday is preferred. Biting your nails is disliked, so use clippers. The Hanafi texts dislike cutting nails and hair while in a state of janabah (major impurity), so do it after ghusl if you can. Long nails can trap dirt that stops water reaching the skin in wudu, so keep them short; see how to make wudu.
The clippings. Bury them if you can, or wrap them and put them in the bin. Do not throw them in the toilet or the shower drain. For the rest of the fitrah, see body hair.
The evidence
Quran, Surah Al-Baqara 2:222
وَيَسْـَٔلُونَكَ عَنِ ٱلْمَحِيضِ ۖ قُلْ هُوَ أَذًۭى فَٱعْتَزِلُوا۟ ٱلنِّسَآءَ فِى ٱلْمَحِيضِ ۖ وَلَا تَقْرَبُوهُنَّ حَتَّىٰ يَطْهُرْنَ ۖ فَإِذَا تَطَهَّرْنَ فَأْتُوهُنَّ مِنْ حَيْثُ أَمَرَكُمُ ٱللَّهُ ۚ إِنَّ ٱللَّهَ يُحِبُّ ٱلتَّوَّٰبِينَ وَيُحِبُّ ٱلْمُتَطَهِّرِينَ ﴿٢٢٢﴾
And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."
Cleanliness and grooming are loved by Allah.
Sahih al-Bukhari 5891
Sahih... الفطرة خمس الختان والاستحداد وقص الشارب وتقليم الأظفار ونتف الآباط ...
"Five things are part of the fitrah: circumcision, shaving the pubic hair, trimming the moustache, cutting the nails and plucking the armpits."
Cutting nails is part of the natural way.
Sahih Muslim 258
Sahih... وقت لنا في قص الشارب وتقليم الأظفار ونتف الإبط وحلق العانة ...
"We were given a time limit for trimming the moustache, cutting the nails, plucking the armpits and shaving the pubic hair: not to leave them more than forty nights."
The 40-day limit.
Sahih al-Bukhari 168
Sahih... كان النبي صلى الله عليه وسلم يعجبه التيمن في تنعله وترجله وطهوره ...
"The Prophet liked to begin with the right in putting on his sandals, combing his hair and purifying himself."
The basis for starting with the right hand.
Where the ruling is recorded
- al-Durr al-Mukhtar with Radd al-Muhtar, Kitab al-Hazr wa al-Ibaha. The recommended order of cutting the fingernails and toenails, and Friday.
- al-Fatawa al-Hindiyya, Kitab al-Karahiyya, chapter on circumcision, hair and nails. Burying clippings, the 40-day limit, and cutting nails in janabah.
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.