The bladder holds between 12 and 16 ounces of urine. Normally you will feel the urge to void when the bladder contains about 8 to 10 ounces of urine, about as much fluid as in a can of soda. There really are no “normal” voiding patterns. Patterns which do exist range from every 4 to 6 hours to every 6 to 8 hours. Seniors over 65 may void every 3 to 4 hours and at least once during the night. After voiding there should be around 3 ounces left in the bladder