Gronkowski, who has made approximately $45 million in his NFL career, told Maverick Carter that his net worth is greater than that because he lives off the money that comes from endorsements, namely Dunkin' Donuts and Tide.
"If you see my NFL money, how much I've made -- I got way more than that, baby," the 29-year-old Gronkowski told Carter on Uninterrupted's "Kneading Dough."
The stingy Gronkowski, who is in the midst of a six-year, $54 million contract, said he decided to treat himself with a gold chain last season -- provided he met the following requirements:
"If I hit all my incentives, if I do everything I need to do, get all my bonuses, put all the work in, I got to finally treat myself," Gronkowski said. "It's been eight years and I haven't really bought anything in my career."
The 6-foot-6, 265-pound Gronkowski posted 69 catches for 1,084 yards with eight touchdowns over 14 games last season.
A second-round draft pick of the Patriots in 2010, Gronkowski has been a touchdown machine since joining the team, reaching double digits in five of his eight seasons, including a career-high 17 in 2011.
Gronkowski has surpassed 1,000 yards four times and has 474 receptions for 7,179 yards in 102 career games (89) starts. His 76 touchdown catches rank third on the all-time list among tight ends, behind Antonio Gates (114) and Tony Gonzalez (111).