At a guess perhaps slightly less, the same, or slightly more.
You lose water vapour as you breathe, and urination only excretes extra water your body doesn't need, so you might lose a bit to the atmosphere and end up weeing less.
As your body breaks down food, and especially fat, water is produced as a byproduct. You (or at least I) tend to go for a wee first thing in the morning even though it is many hours since the last drink. Some of this is a byproduct of metabolism.
If your body excretes some water via breath and sweat, but releases some water from metabolic functions, and you are fully hydrated then you may wee out the same as you drank.
One final factor - how fast are your kidneys? Mine are very slow so it would take more than an hour to shift the 500 ml of water. Others I know are much faster.