@Marged14 Yes - when listening to Pandora on most mobile devices, we use a highly-tuned 64Kbps AAC+ codec for the high-quality setting.
That works out to 8.2 KiloBytes (8.2KB) per second, or roughly 500KB per minute. Figuring in additional content, such as information about the music and advertising, usage will likely be in the neighborhood of 35MB per hour.
The Normal quality setting is half of this figure.
Since there are a lot of external variables at play, it's not possible for me to give a more concrete answer regarding your usage.
Most cell phone providers do offer the option to track your monthly data usage. The best thing to do is familiarize yourself with the specifics of your own data plan. For example - check your data before using Pandora, listen to Pandora for 30 minutes, and then check your data usage again. This should give you an idea of how much data Pandora will use on your device.
It might also be helpful to contact your mobile service provider directly. They should be able to provide you more information about:
Your prior data usage
How to monitor your usage
Average data usage from others on your network while using Pandora
How to avoid overage charges
What to expect when/if you do go over your data limit
We also offer Pandora Plus or Pandora Premium for a monthly fee that include offline listening options for those times when you need to save on your cellular data usage.