Now your tax return is just late. If you are getting a refund there is no penalty for missing the April 15 deadline. If you owe tax due, then your penalty/interest has begun to accrue. Get your tax returns filed ASAP. The extension you wanted to file was not going to give you extra time to pay--it was going to give you extra time to get your documents in order.
The interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**