Washington is home to 16 billionaires. How much are they giving away?

March Madness could be a dream come true — not just for a Cinderella team in the Final Four, but for the against-all-odds sports fan who picks a perfect bracket.

Berkshire Hathaway and Quicken Loans are offering $1 billion to anyone who correctly predicts the outcome of every game in the 2014 NCAA men’s basketball tournament.

You read that right: A billion dollars.

That’s one way to join the billionaires club, that rarefied group of the super-rich who earn more money in one day (or hour) than most of us do in a year. Forbes released its annual list of the world’s wealthiest last week, with a record 1,645 billionaires — including 268 newcomers who hit it really, really big. Topping the list? Bill Gates, worth an estimated $76 billion.

The Washington area now boasts 16 individuals with a personal fortune of $1 billion or more. (One more if you count Commerce Secretary Penny Pritzker, the Chicago heiress worth $2.3 billion who reportedly bought a house in the District last fall.)

Leading the list, at least when it comes to public philanthropy, is David Rubenstein, who went on a spree last year: $121 million in donations, including $50 million to the Kennedy Center, $10 million to the National Gallery of Art, and $10 million to Mount Vernon. In 2010, the Carlyle Group co-founder signed the Giving Pledge, the public initiative created by Gates and Warren Buffett that asks billionaire signatories to commit to donating the majority of their fortunes to charity. Rubenstein, who lent a $22 million copy of the Magna Carta to the National Archives and gave $7.5 million to repair the Washington Monument, is the only local billionaire on the Chronicle of Philanthropy’s list of America’s 50 most generous donors in 2013.

He’s a hard act to follow, but we got curious: How much have the other Washington area super-rich given away?

“It can be very difficult to know if they don’t publicize their giving,” says the Chronicle’s Maria Di Mento, who’s been writing about philanthropists for a decade. “What gets publicized is only a small fraction of what’s happening.”

With all the talk of income inequity and One Percenters, there’s a lot of pressure to give back in a very visible way. The old tradition of low-key charity has been replaced with high-profile philanthropy designed to encourage other donors to step up. “And it does work,” says Di Mento. “It’s a very powerful tactic.”

Even so, some billionaires prefer to keep their philanthropy private. One major American donor, says Di Mento, opted to give a major gift anonymously so his alma mater wouldn’t find out.

Which means someone could be giving substantial amounts every year — or not a dime. Privacy can be a convenient excuse for the cheapskates who rarely crack open their checkbooks.

We decided to take a quick, unscientific look at recent giving from our local billionaires. We contacted their foundations and companies; some called back, some didn’t. The snapshots of giving in the past decade or so include any public donations announced by the donor or beneficiaries and major contributions listed on recent IRS 990 forms, the annual report of charitable foundations’ fundraising and giving.

Names: Forrest Mars Jr., John Mars, Jacqueline Mars

Worth: $60 billion ($20 billion each)

Forbes ranking: No. 31

Source of wealth: Mars, the world’s largest candy company

Homes: Virginia, Wyoming

Signed Giving Pledge: No

Areas of interest: The Mars siblings, who inherited a fortune and built it into an even bigger fortune, have always been notoriously secretive, so there’s virtually no public record of philanthropy or charitable donations. A few snippets: Forrest and John donated $2 million to Yale. John is listed as a supporter of Mount Vernon, and Jacqueline — who has been even more low-profile since her involvement in a fatal car crash last fall — supports the Washington National Opera and the U.S. Equestrian Team, but there’s no record of how much they gave.

Largest public gift: $11 million by Forrest to Colonial Williamsburg.

Name: Ted Lerner

Worth: $4.2 billion

Forbes ranking: No. 354

Source of wealth: Real estate, owner of the Washington Nationals

Home: Maryland

Signed Giving Pledge: No

Areas of interest: The Annette M. and Theodore N. Lerner Family Foundation and the Washington Nationals Dream Foundation give about $3 million a year to dozens of local charities, including $2 million to the Children’s National Medical Center, $250,000 to Georgetown Day School, $384,000 to build a baseball field in Montgomery County and $175,00 to the Jewish Federation of Greater Washington.

Largest public gift: $5 million to George Washington University.

Names: Mitch Rales, Steve Rales

Worth: $3.8 billion and $3.6 billion

Forbes ranking: No. 396, No. 430

Source of wealth: Danaher Corp., the brothers’ manufacturing conglomerate

Home: Maryland

Signed Giving Pledge: No

Areas of interest: Mitch is one of country’s leading modern art collectors and has poured the bulk of his philanthropy — at least $500 million — into creating Glenstone, his private museum in Potomac. The Mitchell Rales Family Foundation supports a number of local charities, primarily for arts and education: $1 million to the Seed School, more than $1 million to the National Gallery of Art, and $250,000 to the Hirshhorn Gallery. His brother keeps a very low profile; there’s no record of public donations.

Largest public gift: Mitch gives $100 million or more each year to the Glenstone Foundation.

Names: Bill Conway, Dan D’Aniello, David Rubenstein

Worth: $3.1 billion each

Forbes ranking: No. 520

Source of wealth: The Carlyle Group, a private equity firm

Home: the District, Virginia, Maryland

Signed Giving Pledge: Yes (Rubenstein)

Areas of interest: The co-founders of the Carlyle Group have become the go-to guys for public charity. Conway has given $5 million each to the Capital Area Food Bank, the University of Virginia and So Others Might Eat. D’Aniello just announced a $20 million gift to the American Enterprise Institute. Rubenstein has become the public face of D.C. philanthropy with major donations to arts and historical institutions.

Largest public gift: $50 million to Kennedy Center from Rubenstein.

Name: Kevin Plank

Worth: $2.4 billion

Forbes ranking: No. 731

Source of Wealth: Under Armour, his athletic clothing line

Home: Maryland, the District

Signed Giving Pledge: No

Areas of interest: The former University of Maryland football player has been very good to his alma mater, giving generously to the business school and athletic programs. Under Armour and his Cupid Foundation donate about $1 million a year to several education programs in Washington and Baltimore.

Largest public gift: More than $1.4 million to the University of Maryland.

Name: Bernard F. (Frank) Saul II

Worth: $2.3 billion

Forbes ranking: No. 764

Source of Wealth: Chevy Chase Bank

Home: Maryland

Signed Giving Pledge: No

Areas of interest: The very private Saul is said to be a generous donor to the arts, the Smithsonian Institution and his alma mater, the University of Virginia, but there’s no disclosures and he never talks about it.

Largest public gift: None announced.

Names: Richard and Bill Marriott

Worth: $2.billion 3 and $2.2 billion

Forbes ranking: No. 764, No. 796

Source of wealth: Marriott Hotels

Home: Maryland

Signed Giving Pledge: Yes (Richard)

Areas of interest: The bulk of the philanthropy goes through the J. Willard and Alice Marriott Foundation, which gives away about $20 million a year in small donations to hundreds of local and national charities: $600,000 to the Children’s Hospital Foundation, $400,000 to the Kennedy Center, $200,000 to the New Schools Venture Fund. Richard and Bill have smaller individual foundations.

Largest public gift: $1 million each to Boston’s Children’s Hospital and the Culinary Institute of America.

Name: Kenneth Feld

Worth: $1.8 billion

Forbes ranking: No. 998

Source of wealth: Ringling Bros. and Barnum & Bailey Circus

Home: Maryland, Florida

Signed Giving Pledge: No

Areas of interest: The Feld Family Foundation has a theatrical bent, donating to the Signature Theatre, the Smithsonian, the New York’s Actor’s Fund, the Theatre Development Fund and the Ringling Museum. Locally, the Duke Ellington School of the Arts has received about $1.2 million over the past six years.

Largest public gift: $10 million to Boston University, Feld’s alma mater.

Name: Steve Case

Worth: $1.2 billion

Forbes ranking: No. 1,372

Source of wealth: AOL

Home: Virginia, Hawaii

Signed Giving Pledge: Yes

Areas of interest: Case is all about health, education and technology, with gifts of $10 million to Punahou School in his home state of Hawaii, $10 million to Habitat for Humanity, $5 million to the Special Olympics, and $2 million to Venture Philanthropy Partners, among many others.

Largest public gift: $22 million to PowerUp, an initiative to provide computer training to disadvantaged students.

Name: Dan Snyder

Worth: $1.2 billion

Forbes ranking: No. 1,372

Source of wealth: Marketing, owner of the Washington Redskins

Home: Maryland

Signed Giving Pledge: No

Areas of interest: The Snyder Family Foundation has donated to dozens of local charities, including $200,000 to the Children’s National Medical Center. Now, Snyder has switched the focus of his public giving to the team’s foundation. The bulk of his philanthropy goes through the Washington Redskins Charitable Foundation, which gives $200,000 a year to Youth for Tomorrow and other educational programs, as well as maintaining football fields around the region.

Largest public gift: About $1 million a year from the Redskins Foundation.

Bonus local billionaire

Name: A. James Clark

Worth: $1.6 billion

Forbes ranking: No. 1092

Source of wealth: Clark Construction, real estate

Home: Primarily in Florida, but Clark also maintains a residence in Maryland and has contributed generously to local charities.

Signed Giving Pledge: No

Areas of interest: Clark and his foundation concentrate on engineering scholarships, recently giving $8 million to George Washington University. He also kicked in $6 million for the USO Center at Walter Reed.  

Largest public gift: $20 million to the University of Maryland.