It is often surprising what passes for “financial planning.”

I met a woman at a Christmas Day party who told me about the strategy that her financial planner recommended for saving money for her child’s college education. The planner told her that his “rule of thumb” is that parents should save one year of college costs in the child’s first year. In other words, make a lump sum investment of one year’s worth of college costs for your newborn and you don’t have to save any more.

If only.

I pointed out that college costs are rising in excess of 5 percent per year; it was hard to see how a lump sum investment could grow quickly enough to offset such a fast rate of tuition inflation.

She responded that her planner made that projection when investment returns were higher than people forecast today.

I don’t make a habit of taking a financial calculator to parties (because I want to be invited back), so when I got home I made a spreadsheet. I wanted to see how fast the lump sum would have to grow to pay for four years of college. I assumed it was invested for 18 years (tax free, as in a 529 plan), while college costs rose by 5 percent each year.

The result? The investment would have to grow 14 percent annually to cover the costs. You can check projected college expenses yourself with this online calculator: http://www.finaid.org/calculators/scripts/costprojector.cgi.  Even in the best of times, no responsible financial planner would project such high returns.