Twitter is a social media site that allows users to express themselves 140 characters at a time. Twitter is free to signup for, but that hasn't stopped Time Magazine from telling users exactly how much their Twitter accounts are worth.

Time put together a Twitter value calculator that measures a users tweets per day, the potential reach of those tweets, and a whole bunch of other mathematical mumbojumbo in order to achieve the account's dollar value.

Here's how the numbers came out when we put in a couple famous Twitter accounts:

Justin Bieber:

Pope Francis:

Rob Perillo:

Frankly, we think Rob Perillo is getting robbed. That man's Twitter account is priceless. Click the button below and find out how much your account is worth. Let us know in the comments section.