Three things to know about the $40 trillion federal debt

JUST IN: US federal debt hits a record $40 trillion, having doubled since 2017, with interest payments alone now costing the government more than $1 trillion a year.

Forty trillion dollars. That's the new US federal debt record, and it's doubled since 2017.

Let me put that second number next to it, because it's the one that actually stings. Interest payments alone now cost the government more than a trillion dollars a year. Not roads, not schools, not aircraft carriers. Just the bill for borrowing. The Treasury is writing a trillion-dollar cheque every year for money it already spent, and you can see the building where those cheques get signed right here.

Nine years to double. That pace used to take generations. And every trillion added gets financed at today's rates, not the near-zero rates of the 2010s, which is why the interest line is growing faster than almost anything else in the budget.

Congress has watched this number cross thirty, then thirty five, now forty, and the debt ceiling fights change nothing about the direction. Interest is now one of the biggest single expenses the American government has, and unlike everything else in the budget, nobody gets to vote on it.

This is Sara White, reporting for HIT.