what is your profit without depreciation?
use 24% of that.
If that is unreasonable, be aware,
You don’t need to file Form 4868 if you pay all or part of your estimated income tax due and **indicate that the payment is for an extension** using IRS Direct Pay, the Electronic Federal Tax Payment System, or using a credit or debit card. Your extension is then automatically granted and you will receive a confirmation number for your records.
Any amount will do.
You only have to achieve 80% of your final tax due with request for extension to be in good graces with the IRS.
