What's My Potential Estate Tax? This calculator helps estimate your federal estate tax liability. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Share | Related Content When Do You Need a Will? When do you need a will? The answer is easy: Right Now. A Brief History of Estate Taxes Federal estate taxes have long since been a lucrative source of funding for the federal government. What Is My Current Net Worth? Use this calculator to estimate your net worth by adding up your assets and subtracting your liabilities.