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 Special Care Is Needed: The Special Needs Trust A special needs trust helps care for a special needs child when you’re gone. Planning for Special Needs Children Planning for a special-needs child can be complicated, confusing, and even overwhelming. Principles of Preserving Wealth How federal estate taxes work, plus estate management documents and tactics.