Having a credit card is a wonderful convenience for those times when you don't have immediate access to your cash. It can allow you to purchase something on time for which you can pay later, thereby giving you the ability to afford something NOW that you'd have had to save for later. But buying on credit will also cost you money - in that way it's no different than taking out a loan to buy something that you want. There are, however, ways to save money when you buy with credit cards.

0% Balance Transfers

One of the most common ways to save money with credit cards is by transferring your balance from a high interest credit card to one with a low or no-interest card. It's easy to illustrate your savings there. If you are carrying a balance of $1000 on a credit card that has a 19% APR and transfer it to one that offers 0% introductory APR for 9 months and a 15.9% regular rate, here's how your savings stack up:

Interest on old card for one year:

1000
x .19
$ 190 annual
$ 15.83 per month for 12 months

Interest on new card for one year:

1000
x 0
$ 0 per month for 9 months

$1000
x .159
$ 159 annual
$ 13.25 per month for three months

for a total of $39.75 for the year.

That's a total savings of $159.25 for one year.

You can, however, save the full $199 by paying off the entire $1000 during the 9 month introductory period.

Save money on credit cards with lower interest rates

It's fairly obvious that you'll pay less in interest charges if you choose a card with a lower APR, but before you jump for the card with the lowest interest rate, take the time to figure out your own buying habits. If, for instance, you tend to carry no balance or a very low balance from month to month, a low interest rate matters far less than say - a good rewards or cash back program, or no annual fee. If, on the other hand, you carry a balance from month to month, the APR is the biggest determining factor in how much your credit card will cost you.

Just as an example, if you generally carry less than $100 on your credit cards from month to month, even an interest rate of 19% only works out to $19 a year, or $1.58 per month. In that case, it makes little sense to choose a credit card that offers a 10% APR with a $29 annual fee.

On the other hand, if you carry a $500 balance from month to month, you'll pay $95 in interest for the year at 19% - but even adding in a $29 annual fee, you'll only pay $79 for the year at 10%.

Don't just assume that the lowest interest rate is the least expensive card. Do the math - and save money with your credit card.

Save Money with Your Credit Card Rewards Program

Cash back and reward points programs are another way to save money with your credit card. If you use your card often but still manage to keep your balance low, you can save 1-5% on purchases that you'd make anyway. Many cards these days offer 5% cash rebates on any purchases made at gas stations, convenience stores and supermarkets. In many cases, those rebates are applied directly to your bill. If you purchase your groceries with your credit card AND PAY THE CARD OFF immediately, you'll end up saving 5% on your grocery bill all year long.