[fintstone]

The mistake that most people make is they do not consider both themselves and their spouse at the same time. You need to do both and consider longevity of both of you at the same time. Although in almost every case, if you live a long time...both of you get more money of both live to 70 (assuming you do nothing with the only you got earlier investment-wise)...but the math changes if she is getting her's because of you, not her work...or if you die (she gets the amount you got or hers...whichever is higher) Personally, it appears to me that in most cases, one or both of you should start at 62...(or when you stop working if older). For example, if my wife takes hers now on her income)...she will start to get my higher amount when I die (if I die first)...so I might want to wait. I won't and will start mine as soon as I stop working (or certainly no later than my full retirement age of 66) because I have plenty for her/us otherwise and everything will be long paid off by 70 (where I have to start taking massive amounts out from my 401K. Best bet is to work out every permutation. This is a great calculator that does just that:
SSAnalyze - Bedrock Capital Management