remember the Motley Fool is a hardcore DIYer's resource. you can seek input from a professional. in fact, i advise it.
a common mistake i see people make that causes them to panic after using those calculators is that they forget to subtract the amount they save and invest every year now, from their future income needs.
another bigger mistake is that they recognize that inflation means they'll need more to spend later, but they forget that the markets historically outpace inflation so the money you already have will also grow substantially.