So how do their contracts compare when contrasted to their respective performance?
Let's break it down.
Johnson's new deal includes $60 million if he remains with the Detroit Lions through the 2019 season.
Fitzgerald's eight-year, $120 million deal, which he signed just last season, guarantees him $50 million and will keep him with the Cardinals through 2018.
And just like each of their monster contracts, their production on the field is eerily similar.
Since 2007, when Calvin Johnson broke into the NFL, each player has accumulated 49 touchdown catches and they are within 700 reception yards of each other.
So what makes Megatron worth $12 million more than Fitz?
Well, the Lions superstar is two years younger than his Cardinals counterpart and he has three years less NFL wear and tear on his body.
He is entering into the prime of his career, having caught an NFL best 16 touchdowns last season, and he is building serious chemistry with quarterback Matthew Stafford.
However, the largest factor in getting the deal done one year before Johnson's contract expired was clearly the Lions' salary cap issues.
Is Johnson worth $12 million more than Fitzgerald?
The 2012 salary cap is set at $120.6 million and the Lions began the offseason a reported $11 million over that benchmark.
Signing a long-term deal has reduced the $21 million Detroit was going to have to pay Johnson this season down to somewhere around $12 or $13 million, a significant drop.
If Johnson went without a new deal he would have been eligible for a $26.4 million franchise tag in 2013 and a $31 million tag in 2014.
Megatron had all the leverage in these negotiations and the Lions front office knew it.
So, if you are wondering if Calvin Johnson is really $12 million better than Larry Fitzgerald, the answer is probably no, but he picked the right time to need a new deal.