So you want to know about which bitcoin address you have the key for.Then in that case you can use any bitcoin wallet to do that.Just head over to import a private key and it will show you bitcoin address.Simple

I don't know which wallet you are using but I can show you how to do it with blockchain.info web wallet:-

1)Head to Import/Export Section and paste the import key and hit the "Add private key"


2) You will get a popup like below showing you the bitcoin address.