By David Mayo, special for BoxingScene.com.

LAS VEGAS -- Floyd Mayweather will earn the biggest guaranteed purse in boxing history, $32 million, when he fights Miguel Cotto, according to contracts filed with the Nevada State Athletic Commission.

They fight Saturday night, at MGM Grand, for Cotto's World Boxing Association super welterweight title.

Because Mayweather's contract also includes pay-per-view percentages, he figures to earn more than four times the $8 million purse for the champion Cotto.

The biggest previous guaranteed purses in boxing history were $30 million, for Mike Tyson in his second loss to Evander Holyfield, in 1997, a fight best known for Tyson biting a chunk out of Holyfield's ear; and for Lennox Lewis when he knocked out Tyson in 2002.

Mayweather's largest previous guarantee was $25 million for last September's victory over Victor Ortiz.

The largest take for a single fighter in boxing history is an estimated $53 million, for Oscar De La Hoya, when he lost to Mayweather in 2007.  De La Hoya's base purse was $23.3 million and he made the rest on pay-per-view and residual income.

Email David Mayo at dmayo@mlive.com and follow him on Twitter at twitter.com/David_Mayo