The average credit card provides a 20 to 30 day grace period. What that means is your credit issuer will not charge interest on your new purchases during this time period. It's probably as close to an interest-free loan as you will ever get. However, grace periods don't work the same on all credit cards, so it's important to read and understand your credit card's billing statement.
The key is to determine whether your "average daily balance" calculation includes or excludes new purchases. If new purchases are included, you will likely lose the grace period if you carry any balance at all from month to month. If the average daily balance computation excludes new purchases, you will enjoy the interest-free loan whether or not you carry a balance.
