Therin lies the rub. There's lifespan and then there's the quality of that span. In my state the average cost of a full-time nursing home is approaching ten grand per month. That kind of money can decimate a retirement portfolio in fairly short order. Unless you started very young and were very aggressive and a bit lucky. It's a moving target.

Plus, I like toys. None of the calculators I have seen say, "And you can afford (to buy, maintain and feed) one of these!"