It’s tough being a parent. But modern parents are making immense financial sacrifices to raise and educate their kids, regardless of the cost to their everyday lives and even to their eventual retirement.

That’s the finding of a study by Merrill Lynch and Age Wave, “Financial Journey of Modern Parenting: Joy, Complexity and Sacrifice.”

The kids, by the way, have no clue. According to presenters at a web briefing, to them all that parental financial support is simply “the way it’s always been,” and that’s part of the problem.

It costs more than $230,000 to raise one child to age 18, and 90% of parents are taken aback at how much they’ve spent to do so. Even when the kids are grown, parents don’t stop opening the checkbook, even though they’re endangering their own retirements and perhaps even health as they age: They regard it as a lifetime commitment, helping adult children with everything from tuition to rent to weddings to home down payments.

Oh, and groceries, cellphone bills and grandkids’ college tuition. In fact, 79% of parents to early adults give at least some financial support to their children — 31% of whom still live at home. “Parents in the U.S. now spend $500 billion annually on their 18- to 34-year-old adult children,” the report says, “twice the amount they contribute each year to their retirement accounts ($250 billion).”

One thing they’re not doing is teaching their kids fiscal responsibility. Their children expect these things, which can cause serious problems if parents suddenly wake up to the reality of the situation and realize that they can’t keep playing banker of first resort. And even though parents think they’re teaching their kids about managing money, that’s not what the kids are getting out of it — especially when it comes to investing.

While 59% of parents say they’ve taught their kids to invest early and benefit from compounding, just 31% of kids have gotten the message; ditto with the 68% of parents who say they’ve taught them to pay off debt as soon as possible. Just 54% of kids agree.

But parents need help, with many realizing that they’ve overextended themselves in providing for their kids — not that they’re not willing to sacrifice for their children. In fact, most parents say they’re willing to make huge financial sacrifices for them, including taking money from savings accounts, cutting back on their lifestyle, raiding their retirement savings and even coming out of retirement altogether.

However, one suggestion from the study is that parents act as financial role models for their children — which should include not putting themselves in the position of possibly having to depend on those kids at some point for their own financial support.

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