novak djokovic
Defending U.S. Open champion Novak Djokovic could pull down $3.5 million if he claims a second straight title at Flushing Meadows this year. Getty Images

Prize money in tennis continues to grow, and it's the U.S. Open that continues to lead the way. Men's and women's singles champions in 2016 will earn $3.5 million from the $36.3 million that goes to singles tournaments, and the U.S. Open has a total purse of $46.3 million.

But the $46.3 million is just a three-percent increase from 2015, and the smallest growth in recent years. In 2013, the prize money jumped from $25.5 million to $34.3 million, or 35 percent. Since then, the increases have been meager, with a 12 percent increase in 2014 and a 10 percent increase in 2015.

But the prize money has more than doubled since 2009 ($21.6 million) and the U.S. Open offers winners far more than any other Grand Slam. Wimbledon is a distant second in 2016 at $2.58 million, followed by the Australian Open at $2.4 million, and the French Open at $2.23 million.

Losing in the championship round or winning the first three qualifying U.S. Open matches to reach the round of 128 affords players major sums. This year’s runner-ups will receive $1.75 million while advancing out of the first round locks a player into more than $43,000.

For many players, the multi-million dollar prize would be life changing, but for tennis’ superstars it only pads their already deep pockets. According to Forbes' most recent list of the world’s highest-paid athletes, seven tennis players find themselves in the top 100 with Roger Federer sitting at No. 4, Djokovic at No. 6, Rafael Nadal at No. 21, Japan’s Kei Nishikori at No. 29, Serena Williams at No. 40, Andy Murray at No. 74, and Maria Sharapova at No. 88.

Federer earned roughly $60 million in endorsements and $8 million in prize money in 2015. Djokovic, in the heart of his prime, earned $21.8 million to go along with $55.8 million in endorsements.

On the women’s side, Williams is the fourth-highest earning tennis player in the world with $28.9 million in total earnings but $20 million comes from sponsorship deals.