Many holiday shoppers splurged without doing the math on how much they could actually afford. If you find yourself with more debt than expected, here are some tips for tackling it:

Set a deadline. A timeline for when you would like to be debt-free can help you figure out how much to pay toward the cards each month. Say you have $1,000 in credit card debt and set a deadline of being debt free by May. You know you’ll need to pay at least $200 a month, depending on the interest rate.

Tackle one card at a time. Make at least the minimum payment on all your cards, then direct any extra cash to pay off one card as soon as possible. Tackle the card with the highest interest rate first, then go after the others. Say you’re paying $300 to one card and $100 a month to a second card. Once the first card is paid off, all $400 could go the second card.

Be smart with extra cash. Are you getting a year-end bonus? Expecting a tax refund? Use those windfalls to make large payments on your debt, says Rod Griffin, director of public education at Experian, a credit reporting agency. ‘‘Don’t look at these things as free money to spend,’’ Griffin says.

Automate payments. Once you decide how much you can afford to pay toward each card, set up automatic monthly payments with your bank to avoid being late or spending the money elsewhere.

Ask for a lower interest rate. You may save by calling your card issuer and asking them to offer a lower rate. About two-thirds of cardholders who asked card issuers for lower interest rates had their requests approved, according to CreditCards.com.

Consider a balance transfer. If you think it will take longer than six months or a year to pay off the card, you might want to consider transferring the balance to a card with a lower interest rate. But factor in transfer fees and the rate you’ll pay after the introductory period is over.

Get help. If you feel as if you’re in over your head, think about getting help from a credit counselor. The National Foundation for Credit Counseling, a nonprofit organization, may have suggestions on how you can adjust your plan.