Move over, Eli Manning. The biggest contract ever given out by the Giants is about to belong to Daniel Jones.

Taking a cue from co-owner John Mara, who has anointed Jones as the quarterback of the future, general manager Joe Schoen said this week that the Giants’ plan is to re-sign the free-agent Jones and build a Super Bowl contender around him. Jones said he wants to stay put. And both Schoen and Jones dutifully mentioned the caveat of the “business side” of negotiations.

So, what does that “business side” look like?

The Post asked six experts — current or former high-ranking league executives with contract experience, and NFL agents — to determine Jones’ value in a market without a middle ground: There is not a multi-year quarterback contract with an average annual salary between $14 million and $29.5 million.

“Several months ago, an extension could’ve been in the Ryan Tannehill or Kirk Cousins range, and now it could be Dak Prescott or north of that,” said former Jets general manager Mike Tannenbaum, co-founder of The 33rd Team, a website that features NFL content. “He played exceptionally well and won a road playoff game. He’s really earned a massive contract.”

All six experts projected Jones’ average annual salary will be between Tannehill’s $29.5 million (adjusted for the salary-cap inflation since he signed that extension in 2020; a floor of about $33 million), and Prescott’s $40 million. One executive projected the right compromise as a four-year deal averaging $30 million to $35 million — so $120 million to $140 million total, including $80 million to $90 million guaranteed.

One agent said his starting point for Jones’ negotiation would be $35 million per year — or about the median cost for the Giants to place the salary-cap-restrictive franchise tag on the quarterback to keep him from free agency in 2023 ($32.4 million) and again in 2024 ($38.8 million) if a deal is not reached.

Another way to reach that number would be to negotiate off Jones outplaying Cousins — his “best comparison,” a second executive said — in the Giants’ playoff win at the Vikings.

“Kirk signed a one-year extension for $35 million, and I would say, ‘I just beat this guy. I need to be above that,’ ” said Joel Corry, a contracts expert for CBSsports.com and a former agent. “The playoffs for Jones were one step forward, one step back. He has to look at the rest of the market and how other teams are going to look at him. You could be overplaying your hand to say, ‘I’ll take my chances in free agency if you don’t franchise tag me.’ ”

The top of the quarterback market is $50.2 million per year (Aaron Rodgers) and is expected to rise this offseason if Joe Burrow, Justin Herbert and Lamar Jackson sign extensions. The Giants’ biggest agreements were Manning’s $21 million annual average on a four-year deal in 2015 and his $97 million lump sum on a six-year deal in 2009.

“Regardless of other teams’ interest levels, Jones still has all the leverage,” the second executive said, “because what are their other [quarterback] options?”

In contrast to the Yankees’ Aaron Judge betting on himself by rejecting a contract offer before his record-breaking 2022 season and subsequently earning an additional $146.5 million, the Giants (wisely at the time) bet against Jones based on his three-year track record and declined his fifth-year option last May at a $21.3 million salary for 2023. That ship — and any in the same fleet — has sailed.

“I would tell them, ‘The guy you were making that decision on is not the player you have now,’ ” Corry said. “You still don’t know how good Jones can be, which is unusual, because he doesn’t have the full arsenal of weapons to help him out.”

Jones, 25, defied NFL history by ranking No. 7 in QBR, leading the league in interception rate, combining for 22 passing and rushing touchdowns, and leading the Giants to an unlikely 9-7-1 season. He is the first of the 11 quarterbacks whose fifth-year option was declined, since that were implemented in 2011, to make his team regret the decision. He could be the first of the 14 who played on a rookie-contract walk-year to sign an extension.

“He’s worth more to the Giants than anybody else, so they are probably going to pay more than they want to,” a third executive said. “But they should get the structure they want to fit them cap-wise — maybe this year’s number is $20 million, then $32 million and build toward the average — to allow them to do the most other things these first couple years.”

Average annual salary is an unwritten sign of hierarchical respect among elite players, but it’s just one way to measure a deal. Fully guaranteed money and total guaranteed (if a player is not cut) are more telling in terms of strength of a commitment. Those numbers vary greatly from deal to deal.

One of the executives and Corry pinpointed the right numbers as $70 million fully guaranteed and “the neighborhood of $100 million guaranteed.”

“I saw development and progress last year in the eye of chaos,” that same executive said. “He and Jalen Hurts were the two quarterbacks that weren’t known publicly like football people knew them. You can see the talent is there. But he was the same player he was at Duke four years ago until [head coach] Brian Daboll brought it out in him.”

If a deal doesn’t get done by March 7, the franchise tag is the Giants’ trump card. Except, however, that route could be needed to secure free-agent running back Saquon Barkley. If the Giants tag Barkley, that would give leverage to Jones, because then they would have to meet his demands or risk losing him in a quarterback carousel in which Tom Brady, Aaron Rodgers, Derek Carr, Geno Smith and Jimmy Garoppolo could all be on the move.

“If I’m Jones, I try to do a three-year deal and get another bite at the apple,” Tannenbaum said. “With the longer-term extensions, teams are trying to lock in cost certainty for a long period of time. If I was the Giants, I would try to go longer to know I have the most important position taken care of for a decade. There’s always risk, but given his great size, the right character, age and ascending trajectory, I think it’s a risk worth taking.”