Anyone who has children – present company included – knows intuitively that raising them isn’t an inexpensive proposition.

The education expenses alone are enough to make some people blanch white at the prospects of child-rearing.

And now we have even more proof of the high cost of having kids. The Gallup organization has just completed a telephone survey of a large sample of American adults age 18 and over – more than 172,000 of them, in fact.

When Gallup asked these respondents how much they spent on purchases “yesterday” (excluding normal household bills and major purchases), it discovered that those without kids under age 18 reported average daily spending of ~$80.

For those with children under the age of 18? They spent ~$110 on average.

So it’s a pretty significant difference of 35%+ more.

Gallup found similar dynamics at work even when comparing adults within the same income groups.

In every income segment, average daily spending levels were lower for adults with no children … spiked for those with kids under 18 … and then dropped back again when children are over the age of 18.

The reasons for the added spending aren’t difficult to figure out, of course. In addition to basic necessities like food and clothing, there are entire categories of spending that come into play for families raising children: extracurricular activities, athletics and sports, entertainment, toys and so forth.

Gallup also discovered similar “bell curve dynamics“ at work when comparing adults within the same age groups. Whether you’re younger or older, your daily spending rises when you have kids under age 18, then drops back down again.

The bottom line: Having kids is costly.  But they sure do make life interesting, don’t they?

For more Gallup survey results, click here.