After reformatting HD still shows used space?

Hello - I"m trying to reclaim an easystore 2tb external HD for my mac. It was partitioned into two 1TB sections (half time machine/half storage). I used Mac Disk Utility to reformat and it says it worked but still shows 852MB Used? Any ideas what I’m doing wrong or what I need to do different?

Hi uxjeff,

You might have formatted one of the partition of the drive. Please select the drive itself while reformatting it in the disk utility.

NOTE: Formatting is data destructive and cannot be undone.