FACTBOX: How Obama's first federal budget compares

WASHINGTON (Reuters) - President Barack Obama will reveal the outlines of his first federal budget this week, expected to come with a price tag of a little more than $3 trillion -- one-third of which will be added to the mounting U.S. debt.

* Obama's budget will be for the fiscal year 2010 which begins October 1 but the federal government's operations are only funded through March 6, 2009, after Congress failed to finish the annual spending bills for fiscal year which ends September 30.

So lawmakers will have to decide whether to try to wrap up all the remaining unfinished spending bills, $410 billion, or to pass what's known as a continuing resolution that would fund the government's operations through September 30.

* Only three other countries have nominal gross domestic product bigger than the approximately $3 trillion in U.S. spending, India ($3.3 trillion), Japan ($4.5 trillion) and China ($7.8 trillion).

* The expected $1.1 trillion additional debt would be $200 billion shy of the gross domestic product of South Korea and more than the roughly $900 billion the United States has spent on the Iraq and Afghan wars since 2001. The Treasury Department reported the outstanding U.S. public debt stood at $10.6 trillion in January .

* The additional debt from Obama's expected 2010 budget would cost each American $3,666.67 based on a U.S. population of 300 million people.

* A $3 trillion budget is still more than the total assets held by the largest bank holding company, J.P. Morgan Chase & Co. which had $2.175 trillion in assets as December 31, 2008, according to the Federal Reserve.

(Compiled by Jeremy Pelofsky; Editing by Eric Walsh)