Floyd Mayweather's fight against Manny Pacquiao on May 2 will help make the American boxer's 2015 earnings shatter the all-time record for a sportsman's annual pay, Forbes.com said on Thursday.

According to Forbes, Mayweather will be likely to earn at least $150 million and Pacquiao more than $100 million for the welterweight world title showdown in Las Vegas.

The financial news website said payouts could be even higher if more than three million pay-per-views are sold.

Mayweather's haul would be the highest yearly earnings ever by an athlete, surpassing Tiger Woods' record of $125 million in 2008.

Woods currently occupies both first and second place on Forbes' list of all-time highest paid athletes, his earnings of $120 million in 2009 number two on the list.

NBA legend Michael Jordan is next, with earnings of $115 million in both 1997 and 1998.

The highest boxer on the list is former heavyweight world champion Mike Tyson, with earnings of $112 million in 1996.