A 2 year old usually pees every 2 to 3 hours or sometimes sooner.
Some 2 year olds may wait until their bladder is full which takes at least 2 hours and then release the pee all at once either into the potty or into a diaper if they are wearing diapers.
So if your 2 year old is in diapers they might dribble a little pee here and there as their bladder fills and pee the diaper a little at a time.
Or some 2 year olds like mine will hold the pee in until at least 2 hours and keep the diaper dry for 2 hours and then pee all at once.
But he doesn't need changed until he pees another time in the diaper because the diapers are very absorbent and can take at least 2 pees.
If your 2 year old is potty trained or is potty training they will usually go pee every 2 hours or so.
A 2 year old can usually hold their pee for around 2 hours.
Most 2 year olds take around 2 hours to fill their bladder up before they need to pee.
So if you have a 2 year old potty training then you need to take the 2 year old to the toilet every 2 hours or so to pee.
If the 2 year old is still in diapers then they will usually pee every 2 hours and can usually go 4 hours with the same diaper before they need a diaper change.
My 2 year old boy only needs a diaper change every 4 to 5 hours depending on how much he drinks.
There's no need to change the 2 year olds diaper after they pee once because diapers can hold more than a few pees.
My 2 year old boy gets a diaper change at 8:00 AM and at 12:00 PM again at 4:00 PM and once again at 8:00 PM before he goes to bed and then he remains in the same diaper until the next morning.
So unless he poops he goes through 4 diapers per day.
I spend around $1.50 per day for diapering my 2 year old and I'm in no rush to potty train him.
That equals out to less than $50.00 per month for diapers.
As long as your 2 year old is peeing every 2 to 3 hours they are usually hydrated enough.