Number of rak’ahs in fard prayers

1. The Fajr Salaah consists of only two rak’ahs, which are fard (obligatory). Two Sunnah rak’ahs should be performed before this, since the Prophet
never failed to do so even on journey.

2. The Dhuhr Salaah consists of only four rak’ahs that are fard. Four rak’ahs of Salaah before the fard is Sunnah Muakkadah. Two rak’ahs of nafl can also be prayed after the fard, in compliance with the hadeeth mentioned earlier, with regards to nafl prayers, which should be prayed regularly.

3. The ‘Asr Salaah has only four rak’ahs that are fard. Four rak’ahs of nafl could also be prayed before the fard. The Prophet
said: ‘Whoever omits the ‘Asr prayer, all his (good) deeds will be lost.’ In one narration: ‘then it is as if he lost his family and property.’ (Bukhari)

4. The Maghrib Salaah consists of three rak’ahs, which are fard. One should try to perform two rak’ahs nafl before the fard after the adhan (call to prayer). Reported Abdullah bin Mughaffal, the Prophet
said thrice, ‘Pray before the Maghrib prayer,’ adding, when saying it the third time, ‘this applies to those who wish to do so’. (Bukhari, Muslim) So anybody finding it strange that people pray two rak’ahs before the Maghrib fard Salaah should remember that it is a Sunnah of the Prophet
, and no Muslim can object to or dislike a Sunnah. Praying two rak’ahs after the Maghrib Salaah is Sunnah Rawatib.

5. The ‘Isha Salaah consists of four rak’ahs that are fard. Two rak’ahs after that is a Sunnah, and one, three, five, seven or any odd number of Witr before going to bed is also a Sunnah, not wajib (compulsory). Nevertheless he
hardly ever missed the Witr even while traveling and once said ‘Allah is Witr so He likes Witr.’ (Muslim). In Arabic Witr means one or odd.

Number of rak’ahs in Nafl (Voluntary prayers

The Nafl prayers, like nafl acts can usually be done at any time, except the times that the Prophet
has forbidden. These prayers are compulsory or obligatory. They are voluntary, with very great rewards if one regularly performs them.

The following hadeeth is a good example to explain the above: It is reported that Prophet
said ‘whoever performs 12 nafl prayers regularly; Allah will make a house for him in Jannah (The Garden, Paradise). These nafl prayers are: 2 rak’ahs before the Fajr (Dawn prayer) 4 rak’ahs before Dhuhr (noon prayer) and 2 after 2 rak’ahs after the Maghrib (Dusk prayer) 2 rak’ahs after the ‘Isha (night prayer)’ (Reported by Bukhari, Muslim and Tirmidhi)

Source: As-Salaah, pg 45, 48