The presidency is costing Donald Trump.

His net worth has fallen by more than a $1 billion since he descended the escalator at Trump Tower and launched his campaign, sending him plummeting 138 spots on the Forbes 400 list, the magazine reported Tuesday.

His net worth is at $3.1 billion, down from $4.5 billion in 2015, Forbes said.

Trump was the 248th-wealthiest person on the list in 2017, down from 156th the year before.

The latest edition of the Forbes 400 will be published Wednesday.

A number of factors are at play for the decline, including that Trump owns commercial space when e-commerce is destroying traditional brick-and-mortar stores.

Reporters scrutinizing his real estate empire have raised doubts about how much he’s worth, and his brand of divisive politics has negatively affected his resorts and golf properties.

The lucrative deals he made by licensing his name for buildings and products owned by other companies have also suffered a hit.

Trump turned over the operations of the Trump Organization to his sons Donald Jr. and Eric, who defended his father.

“My father made a tremendous sacrifice when he left a company that he spent his entire life building to go into politics,” Eric Trump said in a statement to Forbes.

But while the White House has so far been a net loss for Trump, the report said the presidency could wind up being profitable for him.

His election victory likely added an additional $10 million to the price tag of Trump Tower in any potential sale.

The Boeing 757 that Trump flouted as a symbol of his high-flying success during campaign rallies could fetch an additional $6 million.

And Mar-a-Lago, Trump’s exclusive Florida resort, is estimated to be worth $160 million — $10 million more than before it became the winter White House.