There's retiring and then there's retiring comfortably.

In South Dakota, you won't have to save up as much money to get there, but it will take you a bit longer.

HowMuch.net estimates that the average yearly expenses for someone over the age of 65 in the United States currently sits at $51,624 (not factoring in Social Security). They factored in life expectancy rates, then tacked on an additional 20 percent to the dollar figures for a comfortable retirement, and discovered that the average savings required for retirement is more than $900,000 ($904,452 to be exact).

In South Dakota, you can ease into retirement on much less.

According to the numbers, the Mount Rushmore State is the eighth most affordable place for a comfortable retirement at $738,000.

That's the good news.

The bad news?

South Dakota has one of the oldest average ages of retirement (66).

LEAST EXPENSIVE STATES FOR RETIREMENT (Average retirement age)

  1. Mississippi $618,000 (63)
  2. Tennessee $661,000 (64)
  3. Alabama $ 713,000 (62)
  4. Oklahoma $724,000 (62)
  5. Arkansas $728,000 (62)
  6. Kentucky $738,000 (62)
  7. Kansas $733,000 (65)
  8. South Dakota $738,000 (66)
  9. Texas $765,000 (65)
  10. Missouri $771,000 (63)

In all, there are 15 states that require savings of $1 million or more for a 'decent' life after leaving the workplace.

Not surprisingly, Hawaii is the most expensive place to retire, where a savings of $1.85 million is necessary for a comfortable retirement.

Hawaii and Massachusetts match South Dakota for the oldest average retirement age (66). West Virginia has the youngest average retirement age (61).