As of October 2019, what is the approximate total national debt of the United States?

Historically, the US public debt as a share of gross domestic product (GDP) has increased during wars and recessions, and subsequently declined. The ratio of debt to GDP may decrease as a result of a government surplus or due to growth of GDP and inflation. For example, debt held by the public as a share of GDP peaked just after World War II (113% of GDP in 1945), but then fell over the following 35 years.

In recent decades, aging demographics and rising healthcare costs have led to concern about the long-term sustainability of the federal government's fiscal policies. The aggregate, gross amount that US Treasury can borrow is limited by the United States debt ceiling.

As of June 2019, federal debt held by the public was $16.17 trillion and intra-governmental holdings were $5.86 trillion, for a total national debt of $22.03 trillion. At the end of 2018, debt held by the public was approximately 76.4% of GDP, and approximately 29% of the debt held by the public was owned by foreigners.

The United States has the largest external debt in the world. In 2017, the US debt-to-GDP ratio was ranked 43rd highest out of 207 countries. The Congressional Budget Office forecast in April 2018 that debt held by the public will rise to nearly 100% of GDP by 2028, perhaps higher if current policies are extended beyond their scheduled expiration date. The Congressional Budget Office forecast in April 2018 that the ratio will rise to nearly 100% by 2028.