The carrying cost
Interest on the U.S. national debt
Interest is the cost of financing outstanding Treasury debt. We show one consistent definition here—gross interest expense—and do not quietly mix it with budgetary net interest.
Putting the annual figure on a clock
Source: U.S. Treasury, Interest Expense on the Debt Outstanding (FY2025); GAO Schedules of Federal Debt · FY2025
Gross interest versus net interest
Gross interest expense measures interest associated with Treasury debt outstanding. Budget documents often emphasize net interest outlays, which subtract certain interest income received by the government. Both are legitimate, but they answer different questions. The label and source matter more than the larger-looking number.
Method: all smaller time units above are simple divisions of the same annual source. They are not presented as real-time Treasury payments.
Interest questions
Is interest on the debt the same as the deficit?
No. Interest is one category of federal spending. The deficit is the overall gap between all federal spending and revenue during a period.
Why can interest costs change?
Costs change as debt matures, new securities are issued, interest rates move, inflation-linked securities adjust and the total amount outstanding changes.
Is this gross or net interest?
This page uses gross interest expense on Treasury debt. Net interest in the federal budget uses a different accounting definition and is generally lower.