Forbes attributes the drop in President Donald Trump's net worth to an expensive lawsuit, the costs of his presidential campaign, and a decline in the value of his Manhattan real estate. Patrick Semansky/AP

President Donald Trump's net worth fell $600 million to $3.1 billion over the past year, according to Forbes Magazine's calculations, putting him 92 spots lower on the list of America's wealthiest than he was in 2016.

Forbes wrote that Trump was "the most notable loser" on its list of the 400 wealthiest Americans.

Forbes attributes the drop to a decline in the value of his Manhattan real estate, his $25 million settlement to resolve a class action lawsuit filed against Trump University, and the $66 million he spent on his presidential campaign.

Trump's New York City real estate is worth $1.6 billion, his real estate elsewhere amounts to $500 million, his golf courses and clubs are worth $570 million, his brand businesses are worth $200 million, and his cash and personal assets are estimated at $290 million, according to Forbes. Trump is now ranked number 248 on Forbes's list.

Bloomberg was less generous in its estimation, putting the president's wealth at $2.86 billion this year.

In February 2017, Forbes pegged Trump's net worth at around $3.5 billion, down $1 billion from the previous year. The magazine has listed Trump among the 400 richest Americans since it began publishing its ranking in 1982.

Trump made his wealth and business acumen key pillars of his 2016 presidential bid. He kicked off his campaign by saying he was "really rich" and claimed he was worth at least $10 billion.

But the real estate mogul's wealth has long been a subject of debate among journalists and financial experts who have accused him of consistently inflating his net worth without evidence.

During a 2007 deposition, Trump said his estimation of his wealth depends on his feelings.

"I'm worth whatever I feel," he said, adding, "I would say it's my general attitude at the time that the question may be asked. And as I say, it varies."

Former New York City Mayor Michael Bloomberg, who's $45 billion fortune puts him at number six on Forbes' list, took a shot at Trump's claims about his wealth during a July interview.

"Let me phrase this carefully so you get the message: I don't know how wealthy other people are," Bloomberg told Germany's "Der Spiegel."

"You mean that Trump may not be a billionaire?" the reporter asked.

"I didn't say that," Bloomberg said. "You said that."

Sonam Sheth contributed to this report.