Basically how much do you rely on Social Security.
Example: Your actual (or anticipated) expense is 50K/year, your SS income is 30K/year, then 50/30 is 167% (option 4, 151 - 200%).
You don't have to be collecting SS now. Use the SS income you would be getting when you reach 62, 65, or whatever.
Example: Plan to retire at 55. Anticipated expense is 50K/year. SS income at 62 is 18K. 50/18 is 278% (option 6, 251 - 300%).
Edit: Add Infinity option.
Example: Your actual (or anticipated) expense is 50K/year, your SS income is 30K/year, then 50/30 is 167% (option 4, 151 - 200%).
You don't have to be collecting SS now. Use the SS income you would be getting when you reach 62, 65, or whatever.
Example: Plan to retire at 55. Anticipated expense is 50K/year. SS income at 62 is 18K. 50/18 is 278% (option 6, 251 - 300%).
Edit: Add Infinity option.