The site will feature his trademarked Retirement Wealth Index and his Retirement Affordability Index to help visitors gauge what kind of retirement a hypothetical 65-year old couple can expect to have after 30 years of deferrals at 15 percent into a target-date fund. 

If only everyone were as disciplined as Pfau's hypothetical couple, there wouldn't be all of this talk of a retirement crisis, right? 

Wrong. Pfau's couple began deferring 15 percent long before it was a suggested benchmark. The upshot? At a final salary of $100,000, the retirees, after saving at that rate over 30 years, would have $1.07 million for retirement. 

That sum replaces 38.9 percent of income in retirement. Pfau's research doesn't include income from Social Security or other guaranteed benefits, but regardless, he says that's still not enough money. Experts say retirement income should replace 70 to 80 percent of a workers' final salary. 

"We'd like to see income from a 401(k) plan replace closer to 50 percent of income, and let Social Security and other benefits account for the rest," he said. 

"The 15 percent savings rate is just not fool-proof," he said. "People can save responsibly but have very different outcomes based on things they can't control." 

Namely, says Pfau, interest rates. As historically low interest rates have helped stocks and 401(k)s recover from the financial crisis, they've also ground down fixed-income yields, and that's meant dramatic reductions in income replacement rates from typical target-date funds that shift assets into fixed-income as savers near retirement age. 

The same hypothetical couple in 2000, with the same disciplined deferral rate of 15 percent for 30 years, had a 401(k) generating more than a 100-percent retirement income replacement rate. All told they had about 18 times their final salary in a 401(k) plan to live off in retirement. 

That was before the era of historically low interest rates. 

These days, "it's a very expensive time to retire no matter what you've done," said Pfau. 

The new website comes at time when everyone from the Labor Department to the most cutting-edge plan sponsors and RIAs are searching for benchmarks that can help savers know how much money they will need to save to retire comfortably. 

For the time being, Pfau says the site won't offer an interactive calculator that allows savers of various ages to calculate future needs, but it will be updated monthly to reflect changes in interest rates and market performance.

And it also can be a tool RIAs can use to help sponsors to help motivate younger savers, who in a hypothetical world of permanently low interest rates, may, in fact, want to consider deferring as much as 20 percent of income.

According to a Motley Fool article, at that rate of savings, a 25-year-old earning $50,000 and deferring 20 percent of salary would have $1.55 million at age 65, assuming a 6 percent rate of return. That would be 31 times their salary.

"The simple fact is that someone who saves 20 percent of their income over the long haul should have more than enough to maintain a reasonable standard of living in retirement," Jordan Wathen, the writer of the piece, said.

Sounds like it. But Pfau, for one, recognizes that even the 15 percent savings rate is high for most people and simply beyond their ability, no matter how disciplined their budgeting.

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