US National Debt, One Square per $100 Billion, 1966–2026
Topic: Government & Debt
In this chart: US federal debt
About this chart
Each square is $100 billion of the US national debt, and the squares fill month by month as the total grows, left to right in groups of ten — fifty to a row on a wide screen, twenty on a phone held upright. The year beside a row is when its first square filled, and the figure at its right end is the total when the row was complete. Squares added in the past year are pale with a dark dash, and the next square fills from the bottom as the total approaches it. The headline compares how long the first and the latest blocks of the same size took. The animation runs the record over thirty-eight seconds, holds on the latest month for two seconds, and loops. The scrubber pauses on any month, and the speed can be changed in the controls.
Method
Debt is total public debt outstanding. Through March 1993 it is the quarter-end value from FRED series GFDEBTN, with the months between quarter-ends interpolated; from April 1993 it is the last business day of each month from the US Treasury's Debt to the Penny. Each square is $100 billion: the squares filled in a month are the debt divided by $100 billion, rounded down, and the next square is filled from the bottom to the remainder. Squares fill left to right in groups of ten — fifty to a row on a wide screen, twenty on a phone held upright. The year beside a row is the year its first square filled; the dollar figure at its right end is the total when the row was complete. Squares that filled within the past twelve months are drawn pale with a dark dash, and a square empties in a month the debt falls below it. The headline compares how long the debt took to add its first $5 trillion — from March 1966 to the first month at $5 trillion — with how long it took to add the latest $5 trillion, between the first months at the last two multiples of $5 trillion, each rounded to whole years. The first month is March 1966, the first quarter FRED reports; the last month is the latest complete month.
Data sources
Updated August 2026
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<iframe src="https://dataslapper.com/viz/national-debt-by-100-billion.html" width="960" height="600" style="border:0;max-width:100%" title="US National Debt, One Square per $100 Billion, 1966–2026" loading="lazy"></iframe>Paste this on any page. The visualization is self-contained and loads from dataslapper.com.