Dear Rusty: I am 64 years old and having difficulty working due to my arthritis, but I can continue part time as a podiatrist. I do not know the best way to determine when to retire. What is the formula or a way to determine which is a better choice? Signed: Undecided Dear Undecided: There is a difference between deciding when to retire from working and deciding when to claim your Social Security benefits. For the former, you should consult with a certified financial advisor, but I’ll provide you with how Social Security fits into your personal circumstances. In deciding when to claim Social Security, you should look at your financial needs, your life expectancy, your work status, and your marital status. There is no one formula right for everyone because everyone’s circumstances are different, but here are some things to help decide what is right for you: