Children also become more expensive as they get older, the data show.
Parents spent an average of $12,680 a year on infants, while 15- to 17-year-olds cost $13,900 a year.
"Teenagers are the most expensive," said Mark Lino, an economist at the Agriculture Department's Centre for Nutrition Policy and Promotion, and the report's lead author.
"They eat more, which means they have higher food costs, and they also have higher transportation costs. These are the years when they start to drive, so you add them to your insurance or even buy them a car."
Housing expenses -- calculated as the average cost for an additional bedroom -- amounted to about $3,900 per child in US cities and $2,400 in rural areas for a given year. It was the largest child-related expense, accounting for roughly one-third of total spending.
Other costs included food (18 per cent of total expenditures), child care and education (16 per cent), and transportation (15 per cent), health care (9 per cent), miscellaneous expenses such as recreation and entertainment (7 per cent), and clothing and diapers (6 per cent).
Back when the report debuted in 1960, child-care and education costs accounted for 2 per cent of total child-rearing expenses.
Today they make up 16 per cent as more women have entered the US workforce.
The average cost for full-time child care now exceeds $9,500 per child annually, according to a recent report by Washington-based think tank New America.
Health-care costs have also increased over the years, as families pay larger insurance premiums and face higher drug costs, Lino said. State governments use the report's findings to create guidelines for child support and foster care.
Although children are very costly, they also have many benefits.
But, he says, it's not all bad news. The cost-per-child generally decreases as families have more children, a phenomenon Lino called the "cheaper by the dozen effect."
Families with three of more children will spend 24 per cent less, or an average of $177,544, on each child, according to the report. Only-children, by comparison, will rack up 27 per cent more in expenses than their counterparts with siblings.
"As you have more children, your total costs obviously go up but you're spending less per child," Lino said. "Children can share a bedroom, clothing and toys can be handed down, and food can be purchased in larger, more economical packages."
The rebounding economy has also been good to families. After years of stagnant wages, American families saw a boost in earnings in 2015, when median household income rose 5.2 per cent to $56,600, up from $53,700 a year earlier. That was the largest year-over-year increase in nearly five decades.
The findings come amid reports that Americans are having fewer children.
The US fertility rate -- the number of babies born per 1,000 women aged 15 to 44 -- last year fell to its lowest point on record. There were 59.7 births per 1,000 women during the first three months of 2016, down significantly from a peak of 122.9 births per 1,000 women in 1957, according to data from the Centre's for Disease Control and Prevention.
The study did not include indirect costs of having children, such as foregone income from parents who scale back at work or quit their jobs entirely. Those costs can often exceed what parents spend on housing, education, transportation and other necessities, Lino said.
The cost of college was also excluded from the estimate, as were expenses associated with birth and adoption. Lino estimated that a four-year degree would add an extra $181,480 at private university and $80,360 at a public one.
But, he added, parents shouldn't just think of their children as money-guzzling liabilities.
"Although children are very costly, they also have many benefits," he said. "I haven't studied the benefits extensively, but I think if you talk to any parent they'll tell you their children bring them joy and happiness."
