Around 55% of Americans say they're behind on saving for retirement, a recent Bankrate survey found.

In many ways, that makes sense. A comfortable retirement can seem like a hopeless goal when you look at commonly recommended savings guidelines. Financial firm Fidelity recommends saving at least the equivalent of your salary by 30, three times your salary by 40, six times by 50, eight times by 60 and 10 times by 67.