I heard someone say that if the credit card didn't think they could afford their credit limit, they wouldn't give them such a high one. That person has a lot to learn.

And I'm sure he will.

Credit cards are really costly. It's not a big secret. They are in the business of making money. Really. They don't care if you can make your payment or not, they are going to charge you anyway.

It may seem really great that you can spend $2000 on your credit card and only pay $40 a month. Forget that it's a 18% interest rate, you can afford $40 a month and still have what you want.

Sit and do the math and you will see just how credit card companies stay in business. Have you ever thought about how long it will take you to pay off your credit cards if you only make the minimum payment every month? Get ready to be shocked.

Most credit cards only charge a minimum monthly payment of about 2%-4% of your total balance and interest charges.

Let's assume that you have a really low monthly payment of only 2%. Your $2,000 at 18% interest has a $40 a month payment. Only $10 of that payment is going towards your principal with the remaining $30 going towards interest.

If you only pay your minimum balance each month, you will pay for your $2,000 spending spree for the next 30 years. Whatever you bought probably won't last that long. Over time, you will pay about $5,000 in interest. That $2,000 of shopping really cost you almost $7,000.

Okay, you may still say that it's only $40 a month and you bought something necessary. Let's look at where your money could have been working for you, instead of for the credit card company.

If you had placed the $40 in an investment earning 8%, such as an IRA for example, every month for 30 years, you would have over $60,000. You earned almost $46,000 in interest on your investment.

It's funny how interest can work for you, not just against you.

I understand how easy it is to look at a credit card offer and think of all the things you could buy. The interest may not seem like that much, and you may receive cash back or frequent flier rewards. But unless you really know how the math works, you won't see what they really cost you. There are many calculators online that will show you how much interest you will pay if you only make the minimum payment. You can even see how long it will take you to pay off your credit cards.

Then take the shock and make it work for you. Make the commitment to make interest work for you.

And for your future.

Martin Lukac, represents http://www.RateEmpire.com, a finance web-company specializing in real estate/mortgage market. We specialize in daily updates, rate predictions, mortgage rates and more. Find low home loan mortgage interest rates from hundreds of mortgage companies! Visit http://www.RateEmpire.com today.