Start collecting Social Security before Full retirement, what affect on calculating pct when switching to "half" spouse's when spouse starts?

@mhoran_psprep answered with a great link to a great calculator. At that site I also found an article directly related to my question.

https://articles.opensocialsecurity.com/spousal-benefit-calculation Within this article it says:

If you are receiving a retirement benefit of your own, your benefit as a spouse will be reduced by the greater of:

a) your PIA or (what your benefit would be if you waited to FRA)
b) your current monthly retirement benefit.

This seems to mean if she starts now (early) and receives a benefit of say $400, but PIA is $490, then, when her spouse retires in 5 years and starts collecting, say $2500/mo, she can get her $400 plus half his benefit - $490. So it will be reduced by the difference of what she is getting herself now and what she would have gotten had she waited. So in this example instead of $1250/mo (half of $2500) she would get $1160/mo (1250 - 90), a 7.2% reduction. But she'll also have 5 years at $400/mo in the bank.

I don't have official clarification on this, but the article answered this scenario exactly. Unless someone else knows otherwise, I'll assume this is correct.