How much urine can an adult urinary bladder hold before it becomes uncomfortably stretched?

For an average adult, the urinary bladder typically becomes uncomfortably distended when it reaches a volume of approximately 350 to 400 millilitres of urine.12

While the initial sensation of a need to void is generally felt when the bladder contains 100 to 150 millilitres, the intensity of this feeling increases as more urine accumulates. Although the desire to urinate often begins around 400 millilitres, the bladder is capable of holding more; under voluntary control, an individual may override this urge until the volume reaches 600 to 800 millilitres. However, once the bladder reaches these higher capacities, the desire to urinate becomes urgent and eventually irrepressible.13