Most people have a “happiness number” — the amount of money they need to afford the lifestyle they want and not worry about money.

For the typical wealthy New York family, that number starts at $US100 million, according to an estimate by Town & Country magazine.

Only 0.09% of America’s millionaires are worth over $US100 million.

Even rich people think wealth is elusive.

About 5% of Americans are millionaires. The vast majority of them, about 95% according to a report by Wealth Engine, have between $US1 million and $US5 million — and many think that’s just not enough.

“Many people believe that, along with tangible assets and services, having it all means having some wiggle room — money to cover a major splurge or setback, and more on top of that,” writes Norman Vanamee in Town & Country magazine.

Vanamee consulted experts to estimate the “happiness number” for a hypothetical, wealthy, non-working couple in their forties with two teenage kids in an expensive private school in New York City. They live in a park-side Fifth Avenue apartment, buy art, take private jets, donate to charity, and have a household staff — a chef, driver, and housekeeper — plus two vacation homes. They’re also setting aside $US25 million for each child to inherit.

An analyst from U.S. Trust estimated the hypothetical couple would need to have a net worth of $US190 million to sustain this lifestyle.

Here are some of the costs considered in the estimate:

Real estate : $US18 million apartment on Fifth Avenue facing Central Park, $US2 million for furniture and decor, $US20 million for a weekend home in the Hamptons and a vacation spot in the Caribbean.

: $US18 million apartment on Fifth Avenue facing Central Park, $US2 million for furniture and decor, $US20 million for a weekend home in the Hamptons and a vacation spot in the Caribbean. Education : $US1.7 million per child for a “no-expense-spared educational strategy” which includes private school and tutors, music lessons, sports, trips abroad, and four-year Ivy League tuition.

: $US1.7 million per child for a “no-expense-spared educational strategy” which includes private school and tutors, music lessons, sports, trips abroad, and four-year Ivy League tuition. Philanthropy : $US25,000 annually to sit on the board of a New York City Museum, $US15,000 per table at annual charity event.

: $US25,000 annually to sit on the board of a New York City Museum, $US15,000 per table at annual charity event. Staff : $US150,000 annually for a driver, a chef, and a housekeeper.

: $US150,000 annually for a driver, a chef, and a housekeeper. Art: $US20 million to $US100 million per piece, in a seven or eight piece collection, or about $US1 million annually.

$US20 million to $US100 million per piece, in a seven or eight piece collection, or about $US1 million annually. Health and beauty: $US150,000 annually for wardrobe, grooming, trainers, and cosmetic procedures.

Other experts peg the happiness number at around $US100 million.

“[Billionaires] view $US100 million as the starting point for real money. They call it a hundy. Like, ‘Oh, they made it, they have a hundy,'” Richard Kirshenbaum, New York Observer columnist and author of Isn’t That Rich? Life Among the 1%, told Town & Country. Kirshenbaum says the estimate isn’t his own, but came from several billionaires he’s interviewed.

But Robert Frank, wealth editor at CNBC and host of “Secret Lives of the Super Rich,” said “the number is less relevant than how you earned it and what you’re doing with it.”

Still, having money doesn’t alleviate all anxieties. In fact, it often gives way to new anxieties and worries that are unique to those flush with cash.

“I still feel, to some extent, that I don’t have enough money,” said Thomas Gallagher, a multimillionaire quoted by The New York Times. “Emotionally, I don’t come from money; I got very lucky on Wall Street. I’ve been dealing with a myriad of psychological issues since I retired. I have more money than I had ever imagined, but I still worry — do I have enough, if I live longer than I thought?”

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