To answer this question you need to know the normal range of Glomerular FIltration Rate of kidney. The normal range is about 90- 120 ml/min/1.73 m^2
Let say that the average is 100ml/min/1.73 m^2 and the human has 1.73m^2 surface area. If you convert it into one day, then the calculation would be:
100 ml/min/1.73 m^2* 60 min/hour * 24 hour/ day * 1.73m^2= 144000 ml/day= 144 liters/day