Short answer
In the Hanafi school, taraweeh is 20 rakat, prayed in sets of two after Isha and usually before witr. It is a sunnah mu'akkadah (emphasised sunnah) for men and women. The Shafi'i and Hanbali schools also say 20, the Maliki school accepts 20 or 36, and some scholars today pray 8.
Taraweeh is 20 rakat with ten salams, a sunnah mu'akkadah for every adult man and woman, prayed after Isha and normally before witr. Praying it in congregation in the masjid is sunnah kifayah for the community. A short pause after every four rakat (a tarwiha) is mustahabb, and that is where the name comes from.
Other madhhabs
- Maliki
- The people of Madinah prayed 36 rakat in Imam Malik's time, and the school accepts both 20 and 36.
Explanation
The Prophet ﷺ led the night prayer of Ramadan in the masjid on a few nights, then stopped coming out, explaining that he feared it would be made obligatory on the community. Later, Umar gathered the people behind one imam, Ubayy ibn Ka'b, and said that this was a fine new arrangement. The prayer itself was his sunnah; what was new was the single congregation every night.
Why 20. Reports in the Muwatta of Imam Malik and the Sunan of al-Bayhaqi describe the people in Umar's time praying 20 rakat, with witr making 23. The companions accepted this without objection, so the Hanafi, Shafi'i and Hanbali schools treat 20 as the established practice. The Muwatta also has a report of 11, and scholars have explained how the reports fit together.
The 8 rakat view. Some scholars today pray 8 rakat, based on Aisha's statement that the Prophet ﷺ did not pray more than eleven rakat at night in Ramadan or any other month. The Hanafi scholars understand this hadith as describing his tahajjud through the year, not taraweeh. Both sides are trying to follow the sunnah, so keep the discussion respectful. If your masjid prays 8, you may pray the rest at home.
Is taraweeh a bid'ah? No. It was prayed by the Prophet ﷺ himself and continued by his companions. For the step-by-step method, see how to pray taraweeh, and for praying at home, see can you pray taraweeh at home.
The evidence
Sahih al-Bukhari 2012
Sahih... لم يخف علي مكانكم ولكني خشيت أن تفترض عليكم فتعجزوا عنها ...
"Your presence was not hidden from me, but I feared it would be made obligatory on you and you would be unable to keep it up."
The Prophet led the Ramadan night prayer in congregation, then stopped only out of concern that it would become obligatory.
Sahih al-Bukhari 2010
Sahih... نعم البدعة هذه والتي ينامون عنها أفضل ...
"Umar said: What a fine new arrangement this is, though the part of the night they sleep through is better."
Umar gathered the people for taraweeh behind one imam, and the companions agreed.
Sahih al-Bukhari 2009
Sahih... من قام رمضان إيمانا واحتسابا غفر له ما تقدم من ذنبه ...
"Whoever stands in prayer in Ramadan with faith and hoping for reward will have his past sins forgiven."
The virtue of the night prayer of Ramadan.
Sahih al-Bukhari 2013
Sahih... ما كان يزيد في رمضان ولا في غيره على إحدى عشرة ركعة ...
"He did not pray more than eleven rakat, in Ramadan or at other times."
The basis of the 8 rakat view; the Hanafi scholars read it as his tahajjud through the year.
Where the ruling is recorded
- al-Hidaya, Kitab al-Salah, section on the night prayer of Ramadan. It is recommended for people to gather in Ramadan after Isha and pray five tarwihas, each of two salams.
- al-Durr al-Mukhtar, Kitab al-Salah, chapter on witr and voluntary prayers, section on taraweeh. Taraweeh is twenty rakat, sunnah mu'akkadah for men and women, and its congregation is sunnah kifayah.
- al-Mughni (Ibn Qudama), Kitab al-Salah, section on taraweeh. The Hanbali view of twenty rakat.
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.