The volume of urine passed each time by a normal adult will vary from around 250–400ml. This is the same as about two cupfuls. Most people with normal bladder habits can hold on for 3–4 hours between visits to the toilet. Most younger adults can also go right through the night without the need to pass urine.
With ageing, the bladder capacity may get smaller, so the frequency of passing urine may increase, both by day and night.
Also see: Overactive bladder