This is Tomomi. Could you please help me to understand tax accounting. How to find estimated depreciation expense amount from tax returns form. Thank you.

An estimated depreciation expense from the tax form? An estimated depreciation wouldn't be on the tax form. But an actual depreciation should be there. You've got very little information here to go on, and I don't even understand what this "estimated" thing is supposed to be about.

Depreciation should be listed under the deductions section of whatever tax form you're doing, and on the 4562.

If by "estimating" you're meaning to work backwards and figure out what it was on the books of the company from the info on the tax form, if it's an 1120, the difference would be on the schedule M-1, where difference between tax and book is shown. But other than that, I can't think why you'd be "estimating" depreciation off a tax form.

You need to be more specific about what exactly you're doing. Or do you mean figuring out depreciation FOR the tax form, and not "from" it. Either way, you need to clearly state what you're doing.