The rules of thumb I use is: typical bladder is 350 – 500 ml capacity, typical kidneys produce 1 ml of urine per kg of body weight. So typical, well hydrated person weighing 70 kg person will have 350 ml in the bladder in 5 hours. Drink 350 ml can of beer at 10pm before bed and you will wake up at 3 am to pee.
By the way, an interesting side note: Native American Indians would drink a lot of water the night before an early morning raid. They used the urge to pee as an alarm clock. (I don’t remember where I read that so I can’t quote a source.)