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Table 7.1 (PDF)

XLS source file

For each term in office, the President is responsible for four fiscal year budgets starting Oct. 1 of the year they take office and ending Sept. 30, eight months after they leave office. Table 7.1 gives the gross federal debt as a % of GDP at the end of every fiscal year since 1940.  Each President’s federal debt contribution was computed by simply subtracting the value at the start of his first FY from the value at the end of his last FY. 

All Presidents prior to Reagan contributed to paying off the huge WWII debt. The graph also credits the drop in federal debt as a percent of GDP under Clinton towards repayment of the remaining WWII debt and not towards paying off the Reagan-Bush debt. That would simply hide their impact by making it appear that more of the current federal debt was left over from WWII. Had Reagan-Bush simply managed to break even, the WWII debt would have been as low as it’s shown to be.

Debt held by the Federal Reserve System is purchased by printing money; the purpose of these “open market operations” is to put more currency into circulation. The most recent figuresused for this part of the federal debt are available from the St. Louis Fed. This was divided by GDP figures provided by the Department of Commerce.  

Since all Presidents from Truman on have reduced the gross federal debt except Reagan and the Bushes, the part remaining from WWII is found by subtracting their debt contributions (and the FRS contribution) from the current federal debt total.