From my money-saving ezine: With gasoline prices soaring these days, it dawned on me that I should actually do the math on some of the trips that I make, especially the trips I make in an attempt to "save money." Here's how to calculate the cost of your trips:

1. First figure out how many miles per gallon (mpg) your car gets. Mine gets on average 21.1 mpg. (I averaged together the "city" and "highway" figures or actually measure your car's performance.) If you don't know your mpg, you can easily get it by typing in the year, make and model of your car followed by the words "miles per gallon" into any search engine on the Internet.

2. Divide the cost of one gallon of gas (I just paid $3.55 per gallon) by the number of miles per gallon your car gets. I divided $3.55 by 21 miles per gallon. It costs me about 17 cents to drive each mile.

3. Figure out how many miles it takes to get to and from your destination. If you don't know this number, go to "driving directions" within Yahoo Maps (http://maps.yahoo.com/) and input two, complete addresses (in most cases, your home and your destination). That will yield the number of miles between the two locations. If you don't know the address of your destination, use the Internet to locate it first.

4. Double the number of miles you just found to calculate your round trip.

5. Finally, multiply the number of miles in your round trip by the amount it costs you to drive a single mile.

The number you get back will surprise you! It surprised me! For example, there is a thrift store I love to bargain hunt at. It's 14.7 miles from my home. That's 29.4 miles round trip. I used to go at least once a week just for fun. Well, I just did the math, and it costs me $4.99 to go there each time or $22.45 a month. And often, I don't buy anything! If you take a minute to actually do the math, you will likely become more thoughtful about where and when you decide to drive. Your wallet and our environment will thank you.
JR in Houston