The new parenting ideal looks a lot like Katherine and Roger Kranenburg. Professionals who have achieved enough career success to earn both good money and work flexibility, they are raising two children, 5 and 3, who are healthy, energetic and even ask for extra grilled zucchini with their lunch.

In their roomy Washington house, with deck and swimming pool nestled among leafy trees, the Kranenburg family’s mornings look like an upscale version of what more and more American parents strive for: parity in parenting. Dad cooks and Mom untangles hair. Both parents arrange their schedules to make the parent-teacher conference. Dad clicks the kids into car seats; Mom drives them to school.

The Kranenburgs of Northwest Washington are a textbook example of what many of us grew up thinking would be our own parenting style. We looked back at our mother’s housework burdens and career sacrifices or our father’s disengagement with the family, and thought: not for us. We’d match with partners who would trample tired gender roles and commit to support our families 50-50 financially, physically and emotionally. Going halfsies on parenting seemed as obvious as the pants on our legs.

Here’s what this model of shared parenting feels like from the inside:

“It’s chaos,” Katherine Kranenburg, a real estate agent, says one morning. She is still in her mauve bathrobe and talking over her pajama-clad daughter, who sings to a pink stuffed animal to avoid making her bed.

“It’s stressful,” Roger Kranenburg, an energy consultant, says, as he pulls a Spider-Man shirt over his squirming son’s head, ignoring the beeping kitchen timer alerting him that the pasta he’s making for that night is more than ready. “It can really test a marriage.”

Across the country, parents are struggling through what many of us thought would come easily: an authentic split-down-the-middle approach. Is it working?

For a fortunate family like the Kranenburgs, it is, but it’s a no-margin, high-anxiety lifestyle. For the majority of parents who have the ability and inclination to divvy up responsibilities equally, the answer can be more complicated. Subtract the zucchini and the deck, the plush bathrobe and the swimming pool. Add money woes or work rigidity or marital conflict or a child who needs more attention. Voila, we have fathers and mothers reporting unprecedented levels of stress and resentment.

Marriage historian Stephanie Coontz says American parents have higher expectations of themselves than any previous generation. Modern parents, she says, do not realize how much they are up against as they try to change the child-rearing rules while living up to heightened demands. “People don’t anticipate in advance what a strain this will be.” They end up “turning on each other.”

Better, she says, would be “less indignation at each other and more at our society” — our familial infrastructure, the schedules of schools and offices that remain fixed in a two-parent, single-income world.

In Washington public schools, for instance, the 2012-2013 academic calendar includes a two-week winter break, a weeklong spring break, all federal holidays and one city holiday, five professional-development days, four days devoted to parent-teacher conferences and four early dismissal days. Meanwhile, parents employed full time are lucky if they get federal holidays and two weeks of vacation.

The United States is routinely embarrassed in world rankings of family-friendly policies that support a healthy work-life balance. The latest annual Save the Children report on the “State of the World’s Mothers” ranked America at 25, between Belarus and the Czech Republic. Factors such as lower female political status and lower preschool enrollments pushed the United States down the list.

And with more expected of parents, splitting duties is increasingly difficult. Takoma Park father Steve Majors talked about the new demands one evening while he leaned over his younger daughter, coaxing her through three pages of homework. It was his last chore before dinner and after he had logged hours at the office, folded the laundry and supervised his daughters’ bike riding and jump rope.

“Look at this; my parents never did this,” he says, waving a hand in the direction of the homework. “We were told to ‘go outside.’ I never saw my parents.” In the kitchen, his partner checks the simmering lentils and calls out a reminder that dinner will be early because he has to make the evening school meeting.

“We are raising our kids differently [than our parents did]. That’s our decision. But it means we take on all the extra burdens,” Majors says. In other words, just as many are embracing equal responsibility for the family, the parenting part of the equation has grown into an oversize octopus.

“Sometimes I tell people I’m like the guy in the park juggling nine balls,” says Darrell Perry, who lives in the District’s Hillcrest neighborhood and is a lawyer, musician and father of a preschooler and an infant. Before the baby was born, the daily routine for Perry and his wife, WUSA reporter Delia Goncalves, had Goncalves leaving for work at 3 a.m. and Perry waking four hours later to feed and dress their older daughter, construct whichever elaborate hairstyle the 3-year-old had chosen that day, shuttle her to day care, then get himself to his law firm. Goncalves handled the afternoon pick-up and evening routine, and he’d join the family for dinner. Some nights, he might return to work after dinner; some nights, he might rehearse with one of the bands he plays with.

“Conflict? Oh, there was conflict,” Perry says. Now, with a second child and Goncalves just back to work after maternity leave, the schedule is far more complicated. “People think it’s crazy. And it is crazy.”

Some suggest that the burdens for parents might be eased if we demanded more from our employers. Anne-Marie Slaughter memorably made that point last summer in her Atlantic cover story “Why Women Still Can’t Have It All.” One of her remedies was to change “the ‘default rules’ that govern office work — the baseline expectations about when, where, and how work will be done.”

But having a flexible schedule doesn’t mean things always go smoothly. In fact, a recent study from the University of Texas at Austin found that telecommuters work longer hours than office-dwellers. And telecommuters and those with flexible schedules are more likely to have work creep into family time, thus creating more stress, not less.

The Kranenburgs know this from experience. They begin the morning with expectations of what the day will hold. But, if Katherine gets a call from a client or if Roger needs to stay late or if one of the kids gets sick, the day will take any number of radical turns. Their extended families don’t live nearby. They do not have a nanny or backup care, because their jobs are “flexible.” They have friends with kids who trade off the dance commute. Otherwise, they have each other. And, sometimes, that’s not enough. “We are living to the max,” Katherine Kranenburg says, adding that marital tension peaks around the issue of who has to be more flexible on any given night.

Another approach is proffered by Marc and Amy Vachon, a couple who are more committed than most to the idea of shared parenting. They are the authors of “Equally Shared Parenting: Rewriting the Rules for a New Generation of Parents.”

The Vachons lead lives designed to prioritize their home life parity. Amy, a clinical pharmacist, and Marc, a technology specialist, live in Massachusetts and both work 32 hours a week. They do not divvy up responsibilities or keep track of who has done what, a common misperception of their approach, they said in an interview that was, fittingly, joint. Instead, each takes ownership of all aspects of parenting their 7- and 10-year-olds on separate days. If their daughter’s friend wants to schedule a playdate on Thursday, it’s Marc who handles logistics.

The primary elements that keep their “dream” afloat might be considered radical, they acknowledge: lightened workloads and what Amy calls “bravery” to stand up to gender stereotypes.

Which brings us to another major obstacle to changing the traditional parenting dynamics: those internalized gender stereotypes. We are “colliding with 100 years of socialization,” Coontz says. “Despite the fact that we sincerely want to share the pleasures and rewards both of work outside the home and raising a child, there’s still a sense that if somebody has to give more at home and less at work, it should be the woman.”

For mothers, this can lead to an overfull plate. A study published in the American Sociological Review found that mothers endure “contradictory ideological pressures” and thus feel more conflicted about their priorities and end up multi-tasking far more than their partners. They also end up resenting their lot.

Goncalves, for instance, recalls that after her first daughter was born, she thought it her responsibility to cook, clean and care for the baby, even after she returned to a grueling work schedule. She was encouraged to do so by her own mother, who believed it was the womanly responsibility to cook dinner nightly and, if the baby fussed at night, to make sure not to wake a sleeping father. “I got to the point where I just felt too overwhelmed,” Goncalves says. She reached out to her husband, who, she says, had been waiting to be asked. He wanted to be more involved, but he also didn’t want to step over boundaries.

Meanwhile, many fathers also feel too stretched. The Pew Research Center recently found that the majority of fathers today are far more hands-on than their own fathers, but they also believe it’s harder to be a father now.

The New York-based nonprofit Families and Work Institute examined studies on men’s attitudes and concluded in a 2011 report called “The New Male Mystique” that “the ‘ideal’ man today is not only a good employee working long hours to be a successful breadwinner, but is also an involved and nurturing husband/partner, father and son. ... Thus, many men are caught between these old and new worlds and are bound to experience some conflict between work and family.”

For some families, the solution has been to reject the modern ideal.

“I think feminism is one of the worst things for women, because we had totally mastered Donna Reed, home cooking and taking care of the kids thing, and then we ventured out into the workplace, which is great and all, and sent the message that women can do it all,” says Jaime Vargas-Benitez, a mother of three in Alexandria. She says she tried that model in her first marriage, but the stress took too deep a toll. In her second marriage, she and her husband decided to revert to the traditional dynamic. “We made the necessary sacrifices so I could stay home. ... In terms of kids, the division of labor is 90 percent me and 10 percent my husband.” It is working so well, she says, that she looks around incredulously at others who are trying to reinvent the wheel.

But reinventing the wheel is a necessity for families that need two incomes or have partners who want to be equal. And the old wheel doesn’t work for families with same-sex parents, either.

Majors said that he and his partner, Todd Leavitt, have not had to tackle the traditional gender stereotypes, but “we have had to negotiate every single detail.”

One solution they’ve happened upon is to divide responsibilities by proclivity. For Majors, a communication specialist who works full time, that means Leavitt, a part-time landscape architect, takes care of their sprawling lawn. For Leavitt, that means Majors oversees the mornings and he assumes the tasks of cooking and persuading two skeptical girls to taste plantains. The arrangement does not always fall into such neat boxes, and it requires “furious texting” through the day.

Is the conclusion, then, that we are doomed to exhaustion, marital conflict and reams of commentaries about whether we can “have it all” until we accept that earlier generations had it right all along?

Maybe not. One thing all of the couples interviewed had in common was their early assumptions. Each partner thought he or she knew what “sharing” meant and expected it would come automatically. They didn’t realize they needed to define what equal meant to them and to develop a strategy to execute it.

Few had asked themselves if they really wanted to divide responsibilities; if they would take a tag-team approach with one partner stepping back professionally every few years; if they wanted to expand their support network or stay closer to extended family so they’d have backup; or how they were going to field the father-in-law’s eviscerating comments?

Asked “What would you have done differently?,” almost to a person, parents said they would have asked themselves these questions before their first child arrived.

“Experts suggest couples talk about money, commitment, buying a home, religion. ... Nobody tells you to have the conversation about division of labor, about how kids add an extraordinary level of work,” Majors says.

A repercussion of this lack of recognition is that there is little advocacy for structural change. By the time parents realize what they’re up against, they don’t have time to mobilize for political or economic reform on the family front. They’re too busy dashing between the afternoon meeting and ballet class and bickering about who isn’t multi-tasking enough.

“I think what you have to do is recognize together where society is going to push you into traditional roles,” Amy Vachon says. She says she and Marc are vigilant, constantly pointing out imbalances to each other, such as the mother-dominated PTA, and acknowledging when one is veering back toward traditional behavior. “We talk and keep our eyes open all the time. Otherwise, we would fall into the trap.”

Janice D’Arcy is a freelance writer living in Washington and was most recently the author of The Post’s On Parenting blog.