The other day—in her SUV, over coffee and over the voice of a toddler “reading” his book in the backseat—a fellow mom explained her work versus stay-at-home mom dilemma to me in a way I hadn’t considered before.

“It’s not just the money I’m losing now. It’s the money I’ll be losing at the end of my career, too,” she told me, rattling off some six-figure math that shocked me.

Like so many stay-at-home parents, she’s wringing her hands over retirement savings and the potential impact years away from work will have on the position she worked so hard to attain before becoming a mom.

According to the Center for American Progress, parents lose out on way more than just their annual salary when we leave the workforce to care for kids: There’s also lost wage growth, and the loss of retirement plan contributions and benefits. The wage loss calculator developed by the Center for American Progress illustrates how a break from work can cost a parent hundreds of thousands of dollars in the long run.

For example, if you pop in the numbers for a 30-year-old mom making $50,000 who plans to stay home until her child is in kindergarden, you’re looking at a staggering income loss of $539,795.

That’s $200,000 in lost wages, $179,837 in lost wage growth, and $159,958 in lost retirement assets and benefits. Wow.

image 616 Motherly

I have to admit, I didn’t think much about the long game when I decided to stay at home with my son. I was focused instead on the immediate cost of daycare and how it would eat up more than half of my take-home pay, which remains a valid concern. According to a recent report by Care.com, nearly one in three families are spending 20 percent or more of their household income on child care. With that in mind, it’s no wonder two out of three parents say child care costs influence their career decisions. Almost a quarter of parents say they’ve moved to part-time or left the workforce altogether since having kids.

Like so many aspects of parenting, there’s no single solution to this dilemma. For some families, it may make sense for a parent to head back to work fairly quickly and maximize their earning potential. Others may save more (in the short term, at least) by staying home.

Crunched numbers aren’t the only factor here either, as some parents see benefits to staying home or going to work that have nothing to do with income. While balancing careers and kids isn’t known for being easy—perhaps the best thing we can all do is decide what provides the most “worth” for our own families.