One of six American live in poverty, a new report finds, leading to the implication that the US poverty level is even worse than first believed.

The National Academy of Science (NAS) formula calculates the poverty rate to be at 15.8 percent, or nearly 1 in 6 Americans, according to new estimates released this week. That’s higher than the 13.2 percent, or 39.8 million, figure made available recently under the original US government formula, the Associated Press reports.

That government formula was created in 1955 and does not factor in the rising costs of medical care, transportation, child care or the geographical variations of living. Nor does it consider the non-cash governmental aid when calculating income.

According to the revised NAS formula, nearly 18.7 percent of Americans, 65 and older, or nearly 7.1 million, live in poverty, compared to the 9.7 percent, or 3.7 million figure, under the traditional formula. Approximately 14.3 percent of people 18 to 64, or 27 million, live in poverty in the US, compared to 11.7 percent under the traditional calculations. Many of the new poor are the low-income, working people with transportation and child-care costs.

Food stamp assistance is currently at an all-time high of about 36 million.

Nearly 40 million people in the US have lived below the bread line last year as the recession snuffed out jobs and dragged down incomes.

Last year’s poverty rate of 13.2 percent was the highest since 1997, and its rise to over 12.5 percent in 2007 was the first significant bump in four years, said the US Census Bureau’s latest report.

“Real median household income declined by 3.6 percent between 2007 and 2008 … and the decline was widespread,” said the annual Income, Poverty and Health Insurance Coverage in the United States report.

The number of Americans who lived in poverty also rose last year, from 37.3 million people in 2007 to 39.8 million people in 2008.

In the United States, a person or family is considered poor if their income is less than the poverty threshold for their size of household.

The poverty threshold for one person in 2008 was just under USD 11,000, and for a family of four was USD 22,025.

Last year the median US household income — the dollar amount which falls right in the middle of the earning spectrum — dropped 3.6 percent to 50,303 dollars from 52,163 dollars in 2007, a fall that the report blamed on the economic crisis, the worst since the Great Depression of the 1930s.

The drop in the median income was the largest annual decline in household income since 1991, the report said.

Falling incomes were directly tied to the rise in poverty, the report added.