In a sentencing submission on Tuesday, Bankman-Fried's lawyer Marc Mukasey told US District Judge Lewis Kaplan that between 5-1/4 and 6-1/2 years would be an appropriate prison term.
That is far less than the maximum sentence of 110 years he faces after a jury found him guilty in November on seven counts of fraud and conspiracy, in what prosecutors have called one of the biggest financial frauds in American history.
Bankman-Fried pleaded not guilty and is expected to appeal his conviction and sentence.
He acknowledged making mistakes running FTX, but testified at trial that he never intended to steal customer funds.
Kaplan will sentence the former billionaire, who turns 32 next week, on March 28.
The lawyer's submission was accompanied by supportive letters from Bankman-Fried's parents, psychiatrist, and others.
His parents, Stanford law professors Joseph Bankman and Barbara Fried, said their son was uninterested in material wealth and worked hard to make customers whole in the month between Bahamas-based FTX's November 2022 collapse and his arrest on fraud charges a month later.
"Barbara and I ... witnessed firsthand his single-minded focus on getting money back to depositors, long after there was any possibility he would be able to save any of his equity or wealth," Bankman wrote.
Mukasey called a 100-year guidelines range calculated by probation officers "barbaric", saying it was based partly on a faulty assertion that FTX's customers lost billions.
He pointed to the bankrupt company's recent assertion that it expected to repay all customers in full to back up the argument that Bankman-Fried did not set out to steal.
The US Attorney's office in Manhattan is expected to make its own sentencing recommendation by March 15.
Bankman-Fried rode a boom in the values of digital assets such as bitcoin to a net worth Forbes magazine once estimated at $US26 billion ($A40 billion).
His fortune evaporated in November 2022 when FTX declared bankruptcy after a wave of customer withdrawals.
At his month-long trial in Manhattan federal court, three former close associates testified that Bankman-Fried directed them to help loot FTX customer funds to plug losses at his Alameda Research hedge fund, even while presenting himself publicly as a responsible steward in the volatile cryptocurrency market.
Prosecutors said Bankman-Fried also used customer funds to buy luxury real estate in the Bahamas and to donate to US politicians who might support cryptocurrency-friendly regulations.
Bankman-Fried testified that he did not realise how much Alameda owed to FTX until shortly before both failed.
Bankman-Fried has been in a Brooklyn jail since August, when Kaplan revoked his bail after finding that he likely tampered with witnesses.
