The Prophet ﷺ used to take a bath with one Saʿ up to five Mudds (1 Saʿ = [??] Mudds) of water and used to perform ablution with one Mudd of water.  

سَمِعْتُ أَنَسًا يَقُولُ كَانَ النَّبِيُّ ﷺ يَغْسِلُ أَوْ كَانَ يَغْتَسِلُ بِالصَّاعِ إِلَى خَمْسَةِ أَمْدَادٍ وَيَتَوَضَّأُ بِالْمُدِّ