How much tax if any can you deduct on your federal and or state income tax?

Obviously, tax isn't deductible from determining the income that is taxable, for the same tax involved. There is no limit to the amounts. Generally: Federal - State (and city) income taxes and property taxes, (and under a new rule some sales taxes if your in a state without property tax), and of course a plethora of the payroll type taxes may or may not be currently includable in determing Federal taxable income. State Income taxes do not allow their own State (and sometimes other States) taxes to be deducted...essentially you add them back to your Federal Taxable Income. They may also consider some things like Unemployment Ins payments (and other payroll taxes) differently than the Feds. Also generally, to be currently deductible, the tax must have been paid to the jurisdiction, not just what you expect to pay.