The United States spends $746 billion on welfare. That's just federal spending. States also spend their own money lifting the total to $1.03 trillion. Makes your eyes water but it's still less proportionately than NZ welfare spending.
It's almost impossible to do a direct comparison to NZ because the US figure includes medical assistance. The Washington Times article suggests medical assistance makes up 46 percent of the federal spend leaving $403 billion, and most of the state spend. So my guesstimate is $500 billion all-up.
NZ spends $11 billion on welfare. Doing a straight comparison, we're spending half as much again per capita (11/4.4 x 312). That is, if the US spent as much per person they'd be spending $780 billion - not $500.
But our spending is mostly cash transfer whereas in the US its mainly in-kind assistance:
Mr. Kogan said the cash assistance figure was “a shockingly small amount of money” in the scheme of things.
“Virtually all the rest is in the form of in-kind assistance: Medicaid, SNAP, WIC, housing vouchers, Pell Grants, LIHEAP and child care vouchers; or in the form of direct services, such as community health centers, Title 1 education, foster care, school lunch and Head Start,” he said.
Rather than straight transfers, those other programs provide support for services Congress has deemed worthy of funding. SNAP is the Supplemental Nutrition Assistance Program that used to be called food stamps; LIHEAP is the Low Income Home Energy Assistance Program; WIC is the Women, Infants and Children nutrition program; and Pell Grants provide assistance for college costs.