If I owe federal taxes and filed for an extension, what is my due date to pay these taxes?

[Mike9241]

the entire balance due needed to be paid on or before the original due date of 4/15/2025 unless you qualified to pay later due to qualifying for disaster relief. late payment penalties are 1/2% a month for each month or fraction thereof that it's late. interest is added daily. the sooner you pay the sooner the penalties and interest will stop. if you are unable to pay you can apply for a payment plan. the penalties and interest are computed on the unpaid balance not your tax liability. 

https://www.irs.gov/payments 

Turbotax does not compute these penalties and interest. 

[rjs]

An extension is an extension of time to file your tax return, not an extension of time to pay the tax that you owe. Your payment was due April 15. You have already incurred interest and penalties for late payment. The interest and penalties continue to grow until you pay.