United States

The US debt clock takes the most recent official snapshot from Treasury Fiscal Data (Debt to the Penny), the Bureau of Economic Analysis, the Federal Reserve, the Bureau of Labor Statistics, and the Census Bureau, and interpolates each instant with the published annual growth rates.

The method

Every card uses value(t) = base × (1 + g)^((t − t₀) / 1y). Both base and g come from official releases and refresh at the next publication.

Gross federal debt vs debt held by the public

The headline series is total (gross) federal debt from Treasury’s Debt to the Penny. It sums debt held by the public and intragovernmental holdings (such as the Social Security trust funds). The statutory debt ceiling set by Congress applies to this total, and it is not the same as the narrower debt-held-by-the-public figure often used in international comparison. The FAQ and glossary surface this difference explicitly.

Limitations

These are interpolated estimates. Fiscal or monetary policy shocks pull actual statistics off this trend.

Data limits and reliability

The live figures on screen are estimates interpolated between two official releases, and the next confirmed print can revise them after the fact. Not every series carries the same weight either, so each one is tagged by confidence — official (confirmed), estimate (interpolated), or proxy (a stand-in indicator). The headline in particular is total federal debt, so comparing it directly with a debt-held-by-the-public series will mislead; for anything that matters, follow the source under each card and read the primary data yourself.

How to use and cite

When you quote a figure in an article or paper, use the snapshot API (/api/usa/snapshot.json), which pins a single instant. Copy the baseAsOf and citeAs fields from the response and your reference becomes reproducible. To put the numbers on your own page, build an embed in the widget studio (/widget/studio) or call the public JSON API directly. Treat this site as a companion that adds a sense of time to otherwise frozen official statistics — never a replacement for them.

United States About · WorldRealDebt