Serena Williams Is Worth Every Penny

It should have surprised no one to watch the top women's tennis player in the world breeze her way through yet another win, but the crowd went crazy nonetheless. Serena Williams won the first round of the U.S. Open in New York City on Tuesday, beating Vitalia Diatchenko after just 30 minutes. And now Williams is on her way to winning the rare calendar slam — winning all four grand slam titles in one year, which include the Australia Open, the French Open, Wimbledon, and the U.S. Open. With such an unparalleled career already under her belt and this watershed accomplishment on her horizon, it's natural to wonder what Williams' net worth is. The figure is indeed sizable, but the No. 1 female tennis player in the world has earned every cent.

Taking another step toward winning the calendar slam (which only five other single's players have ever achieved), Williams secured her first-round win at Arthur Ashe Stadium in Queens when Diatchenko was forced to surrender due to injury. After the match, she told reporters:

It was definitely different and bizarre. But at the same time, I was still focused. I kept thinking, "Just stay focused. Don’t lose it. You never know what can happen."

True, the future is always uncertain, but based on her recent performance — she won her second "Serena Slam" (winning all four grand slam titles in a row) in July — she's set to become the first female tennis player to win the calendar slam since Steffi Graf in 1988.

With such a consistently strong career continuing to unfold before her, it's not unfathomable that Williams is handsomely paid. Her net worth in 2015 is estimated at roughly $145 million, which is more than most people will ever make in their entire lifetimes. But here's why the world's No. 1 single's player has more than earned her fortune.

She's Won The Grand Slam 21 Times

While the calendar slam is a more elusive feat, Williams is no stranger to winning the grand slam, which requires winning all four major titles in consecutive order — though not necessarily in one calendar year. Only two other women in history hold more titles than Williams: Margaret Court and Steffi Graf.

She's Set Dozens Of Records Throughout Her Career

Over the course of her career, Williams has set dozens of records:

• In 1999, she became the second African-American woman to win a Grand Slam title at the 1999 U.S. Open, and the first to win the U.S. Open since 1958.
• She holds the most U.S. Open titles in the Open Era, after winning her sixth in 2014.
• She holds the most Australian Open titles in the Open Era, after winning her sixth in 2015.
• She is the first woman to win more than 50 matches in all four grand slams in the Open Era.
• She is the oldest player to hold all four grand slam single's titles simultaneously.
• She has the longest span between her first U.S. Open title and her last — 15 years.
• She is the highest-earning female athlete of any sport in history.
• For the first time ever, tickets for the women's singles in the U.S. Open finals sold out faster than the men's singles, and Williams was the reason.

She Has Other Business Ventures

Besides being a world-famous tennis player, Williams is also a savvy businesswoman. In addition to various endorsement deals, including those with Nike and Wilson, Williams has also invested in several companies she endorses, like Mission, Sleep Sheets, and HSN. Speaking of HSN, Williams also has a popular clothing line, Serena Williams Signature Statement, which she sells on the shopping site. She also has a sportier line that she designs with Nike.

She's A Philanthropist

Williams generally shares her wealth through her various philanthropic projects. The main one is her Serena Williams Fund, which aims to help communities prevent violence and have access to education. Williams is also a UNICEF Goodwill Ambassador, and has partnered with various charity organizations around the world, including Build African Schools, the Elton John AIDS Foundation, and Hearts of Gold.