I've spoken with several financial planners who recommend saving at least 15% of income for retirement (media example and this site has an example). They do not include social security, which takes 15% (half I pay, half my employer pays) up to an income limit (around $120-130K).
For people making under that threshold that amounts to saving 30% (15 + 15) for retirement. This sounds like a lot, as that equates to $0.30 being saved for retirement for every $1 earned (granted, employees don't see the part of social security that employers pay, so it only feels like their losing 7.5%).
Is there a reason that financial planners exclude social security in these calculations?