When kids go back to school, many parents spend money for the staples like clothes, backpacks and supplies. But now parents are also shelling out big bucks to keep their kids engaged daily after the end-of-school bell rings. 

Iris Nieves, ThinkStock

According to a new survey by RetailMeNot and The Omnibus Company, parents are expected to spend, on average, $396 throughout the school year to pay for extracurricular activities.  Nearly nine in 10 parents reported that their child participates in extracurricular activities like sports, theater and travel clubs during the school year.

Despite the popularity of after-school activities, many parents aren't prepared for the costs.

"We're finding that parents aren't adequately budgeting for this financial outlay," said Trae Bodge, senior lifestyle editor for RetailMeNot.com.

In fact, the survey showed that three in four parents have spent less on something for themselves in order to cover the costs of their child's education. Some of the items parents have scaled back on include dining out, vacations and clothing.

For parents struggling to pay for after-school activities, Bodge suggested setting some limits on how many activities children can participate in.

Another option is to ask the child for help.  "Maybe you can work out a way with them that they can personally contribute." In addition, many times athletic equipment or even musical instruments are sold with discount coupons in stores or on certain websites.