While it’s true that little is predictable when it comes to having children, it’s as much a financial decision as an emotional one.

After all, the average lifetime cost of raising a child exceeds $233,000, according to the U.S. Department of Agriculture.

That’s a price tag that might leave you wondering: Does it make sense to have a baby in your 20s, so you can tackle child-related costs early — or when you’re in your 30s and, hopefully, more financially stable?

Of course, there’s no blanket answer. But consider the data from these two hypothetical sets of wannabe parents a decade apart in age and how they compare in three major money areas — retirement, college costs and child care.

Meet the Parents-to-Be

Emma and Tyler, are both 26. Emma is an executive assistant. Tyler is a junior accountant. Combined, they make $73,000, and are still paying off student loans and credit card balances they accrued in college.

Although they spend nearly every penny of their paychecks, they’d rather be young parents and are confident they can make their budget work.

Holly and Brendan, both 36, are doing well financially. Their income has grown steadily over the past few years — which isn’t surprising since women’s pay peaks at 39 and men’s at 48, based on data from Payscale.

Between Holly’s job as a project manager and Brendan’s as a human-resources manager, they make $120,000 combined. They’re only a few months shy of paying off their student loans, carry little credit card debt and contribute a portion of each paycheck toward retirement.

They purposely put off having children until they reached six figures, and now feel financially ready for parenthood.

So which couple would fare better?

Baby’s Impact on Retirement

When it comes to your nest egg savings, the real key is to start socking away money as early as possible.

To that point, having Junior at 26 is more likely to cut into prime saving years because younger couples tend to have tighter budgets and don’t contribute as much to retirement, says Rebecca Kennedy, CFP®, founder of Denver-based Kennedy Financial Planning.

Exacerbating the situation is the fact that most people in their 20s don’t think about retirement — baby or no baby. A Principal Financial Group study found that less than one-third of millennials save at least 10% of their income in an employer-sponsored plan.

By the time you hit your mid-30s, however, “you’re more aware of all your financial obligations, and most of the folks who come to me [at this age] have a pretty good balance,” Kennedy says.

Indeed, an analysis of Employee Benefit Research Institute data that compared the nest egg savings of people in their early 30s versus their late 30s found that IRA balances jumped by more than 60% in this decade.

So Who Has the Advantage? Holly and Brendan. Being able to contribute aggressively to retirement before a baby comes along leaves them better able to take advantage of compound earnings, says Steve Erchul, a CPA with Smith, Schafer & Associates in Edina, Minnesota. “Their money could grow astronomically because they started early,” he adds.

If Holly and Brendan saved aggressively from age 26 to 36, each putting $500 a month into their own retirement accounts, which return 7% a year, by 36, they would have nearly $174,000.

Even if they never contributed another penny after baby, compound growth would add up to $1.4 million by the time they retired at 67.

Meanwhile, if Emma and Tyler put off saving as aggressively until 48, when their kid heads to college — each contributing $1,000 per month to their individual accounts to catch up — they’d end up with less than $950,000 combined at 67.

That’s about $450,000 less than Holly and Brendan.

Baby’s Impact on College Costs

In theory, couples can start saving for college even before having a child, but it’s not usually on their radar until a baby arrives, says Kennedy.

If both couples have about 18 years to save, Emma and Tyler have an advantage: their potential eligibility for tuition tax credits.

For example, the American Opportunity Tax Credit (AOTC) — which grants up to $2,500 per eligible student — doesn’t start to phase out for married couples until their modified adjusted gross income reaches $160,000, says Erchul.

So if this credit, or a similar one, still existed by the time Emma and Tyler’s child went to college, they could qualify for it, even if their income more than doubled by the time they reached 44.

But the terms of tax credits are hard to predict, so the real key here is who can contribute the most to a 529 or another type of college savings account.

“From what I’ve observed [of couples in their 20s], there’s not a lot of excess in their cash flow,” Kennedy says. “They’re more in survival mode.”

Holly and Brendan, meanwhile, may have more wiggle room in their budget.

So Who Has the Advantage? Holly and Brendan. They’re likely to contribute more toward college over the next 18 years.

If Emma and Tyler put $50 a month into a 529, returning a hypothetical 7% a year, they'd have a little more than $21,000 in 18 years.

If Holly and Brendan contributed $100 a month, their college investment could grow to more than $43,000.

Baby’s Impact on Child Care Costs

According to member data from Care, the average cost to send one infant to day care is $10,468.

Holly and Brendan seem like they’d be better off — with more income to work with, they should be better able to fit this cost into their budget.

But Emma and Tyler may actually be in a better position when it comes to free child care in the form of family help — Grandma and Grandpa may still be spry enough to run after a toddler.

Of course, there’s always the option of having one parent stay home. In this scenario, Holly and Brendan have the advantage, since “they’re at a higher pay level, so if they drop down to one income, it’s [still] a good income,” Kennedy says.

The hitch?

Many successful women (yes, it's still mostly women who leave work to raise kids) have a hard time re-entering the workforce.

The New York Times reported that only 40% of high-achieving professional women who quit work for a time were able to find a good full-time job in their desired industry once they returned to the workforce.

So Who Has the Advantage? It’s a draw. Yes, child care is a huge expense that Holly and Brendan may be better able to cover — but factoring in family help and career opportunity costs could tilt the odds toward Emma and Tyler.

Plus, you shouldn’t count out the younger generation’s scrappiness when it comes to budgeting, says Michele Clark, CFP®, owner of Clark Hourly Financial Planning in Chesterfield, Missouri.

“I think because [the millennial] generation saw their parents struggle with the stock market, they have more of that Great Depression mentality,” Clark says. “They shop at thrift stores, cook and don’t eat at expensive restaurants.”

Holly and Brendan, meanwhile, are in a demographic that can be susceptible to lifestyle inflation because people their age are used to a comfortable life, and it may only get worse once toddler classes and day camps come into play.

Certified Financial Planner Board of Standards Inc. owns the certification marks CFP®, CERTIFIED FINANCIAL PLANNER™, CFP® (with plaque design) and CFP® (with flame design) in the U.S., which it awards to individuals who successfully complete CFP Board's initial and ongoing certification requirements.