Shamelessly taken from another website:
Raising Your Child: The Costs
According to the 2005 report from the Department of Agriculture, the cost of raising a child to the age of 17 will be approximately $500,000. These costs include:
Housing is the single greatest expense when it comes to raising a child. Housing expenses include rent payments, mortgage payments, furniture, insurance, and utilities. Depending upon your annual household income and where you live, expect to pay between $200 and $400 per child, per month on housing. This can add up to $100,000 by the time your child turns 17.
Food expenses include the cost of beverages, meals, dining out, groceries, convenience and specialty foods. Most parents will find that the cost of feeding their child will increase as their child ages, hitting a peak around the ages of 12 to 17. Expect to pay between $70 and $260 per child each month on food expenses. This works out to as much as $40,000 over a 17 year period.