You might try this parking website which lets you put in your address, see a map and then examine more closely based on date and time. If you are not requiring in and out during your stay consider parking more remotely and using public transportation to get you into the city.

Forgot to put the link. http://chicago.bestparking.com/#1

The least expensive parking near the Hyatt is at the Millennium Park garage. It's about three blocks south and around $25 for 24-hours. http://www.millenniumgarages.com/

When you enter, the complex from Columbus Drive, there are signs that direct you to either the North Grant Park Garage or the Millennium Garage. North Grant Park is a couple dollars more and a bit longer walk to the Hyatt.

Once you arrive in the city, leave your car parked until you depart. If you'll be out-and-about in the city, you may want to get a 1-day CTA pass that allows unlimited rides on all CTA trains and buses. They're available at the CVS or Walgreens just around the corner from the Hyatt.

We were just in Chicago a few weeks ago, stayed at the Hyatt on Wacker, and used the Millenium Garage to which Citylights referred. It's about 1/2 the price of the Hyatt Parking. Although we had scouted it out ahead of time, as we pulled up to the Hyatt to drop off luggage (and spouse), the Hyatt attendants were very helpful in describing how to approach the Millenium garage. It worked out great! Good luck! We really enjoyed staying at that location. Hope you do also.

We also used the Millenium Garage when staying at the Hyatt on Wacker - there really isn't anything cheaper close by.

As laurie_ann suggested, park somewhere more remote. We parked at the airport--either one will work depending on which direction you are coming from. We paid $5/day a few years ago.

If you are flying in, you don't need a car if you are staying in the Chicago area.

I was assuming you're driving into the city. If you're flying, by all means, don't rent a car as you won't need it and you'll pay rental and parking for it to sit most of the time.

If you're only going to be here one night, it wouldn't make much sense to park outside the central city as you'll spend at least an hour each way between the hotel and your car and still have to walk several blocks or take a cab to the Hyatt.

We stayed at the Hyatt in July. They have a Facebook page that will give the word of the week. It saves you $15 off daily parking at the hotel. The valet parking was smooth on drop off and pick up.