Real money/virtual tools

Where to find the lowest gas prices. Whether to rent or buy a house. How risky your investments are.

If it's an issue that involves money, such as these, the chances are there's a tool on the Internet that will help you crunch the numbers free of charge.

Free information, of course, isn't necessarily the best information. But the world of no-cost online tools – for everything from airfare searches to paying down debts – is becoming increasingly sophisticated.

"It's empowering people more and more to do their own planning," says Chris Brockbank, an owner of Financial Calculators, an online-tool creator in Riverton, Utah. Until the rise of the Internet, he says, "You'd read it in a book, but you didn't have a medium ... to do it yourself."

That medium has arrived.

Here's a peek at a dozen such sites – some new, many tried and true. Often they come with disclaimers: They aren't a substitute for the individually tailored advice of a financial professional. And as with any tool, Web calculators are only effective when used properly.

"It all comes down to 'garbage in, garbage out,' " Mr. Brockbank says.

But don't underestimate them, either. You may already have a summer reading list. What these sites promise is a summer math list that might save you time on the financial puzzles in your life and leave you with more time for beaches, barbecues, and good books:

For many diehard users of eBay or Shopping.com, the Web is the marketplace of first resort. But even people who don't take naturally to online shopping may find price-checking sites handy.

To find some of the lowest-cost gasoline in your neighborhood, go to www.gasbuddy.com. Type in your ZIP Code, and – if your area is represented – GasBuddy gives a list of the nearby gas stations where it has found the lowest prices in the past 48 hours.

For airline tickets, surf over to www.kayak.com, which scans multiple websites for the best available prices. Type in your desired itinerary, and in 15 seconds or so, you'll see a ranking of deals available on other airline or travel websites such as Orbitz, Expedia, Delta, or JetBlue. You'll need to log in to one of those sites to actually buy the ticket. Another option, similar to Kayak, is www.sidestep.com.

Wondering what your professional skills might be worth in another city? Click on Salary.com's "Salary Wizard" (www.salary.com in the "tools and resources" section) and you'll find, for instance, that a beginning architect might make about $35,000 in Phoenix, and $39,000 in Santa Barbara, Calif. But before you move from the blazing Arizona desert to cooler Pacific shores, check out the site's "Cost-of-Living Wizard." You'll find that living costs are about 33 percent higher in Santa Barbara than they are in Phoenix.

Another inflation gauge comes from the US Labor Department, at www.bls.gov. Click on the inflation calculator under "inflation and consumer spending," and you can compare the purchasing power of a given amount of money between any two years of your choice.

It's the thing you'd rather not think about but sometimes need to know: How much will you owe in taxes this year? One place to find out is the website of tax-accounting firm H&R Block (click on "tax estimator" at www.hrblock.com/taxes/tools). The site also has tools to help you weigh what should be withheld from your paycheck or whether you'll have to pay a federal "alternative minimum tax."

The Social Security Administration offers several tools to help you forecast what your retirement benefit will be, under different scenarios. Go to www.ssa.gov/ planners/calculators.htm.

The investment-research firm Morningstar Inc. has launched a tool this year for screening the top exchange-traded funds. ETFs, as they're known, can be bought or sold like stocks all through the day but offer diversified holdings like mutual funds. Go to www.morningstar.com, click on "tools," and then on "ETF" in the "screening tools" section. One example of what you can ferret out: Among international exchange-traded funds, a good number of single- country funds have gained more than 10 percent this year. Italy didn't merely win soccer's World Cup, the country's ETF was up more than 14 percent through July 11.

But there's solace for two World Cup runners-up: The ETFs representing Brazil and France are doing even better than Italy's.

Morningstar's tools cover the investing gamut from mutual funds to stocks, and even check the "yield to maturity" of a bond.

The site is free, and premium tools tend to focus on how each investment fits into a whole portfolio, says Kathy Panagopoulos, a Morningstar spokeswoman. "That's why the screening tools and portfolio tools are so popular," she says.

A tool called "Instant X-Ray," for example, will give a quick overview of a portfolio's profile: How the stock or mutual fund holdings compare with the industry weightings and earnings of the Standard & Poor's 500 index, and where the holdings are located on a map of the world.

Investing tools abound on other websites as well.

At www.bigcharts.com, you can get historical price quotes or chart the track record of various investments against one another (click on "interactive charting").

At www.diamond-hill.com, click on "financial model" for a tool that helps estimate what a stock is worth.

At www.riskgrades.com, you'll find various ways to measure whether a portfolio provides the returns to compensate for its risks. Under "portfolio analysis," click on "event risk" to see how your holdings might perform during a repeat of past cases of market distress – such as the "black Monday" crash of 1987.

Then there's MoneyChimp (www.moneychimp. com). This site can calculate annualized rates of growth, run so-called "Monte Carlo" simulations of future investment performance, or test out "modern portfolio theory." In other words, just about all the hairy math you can handle, and no hairy primates in sight.

The dozen websites above only scratch the surface of what's out there. Here are a few other sites that each boast a range of financial calculators.

The tax-information company CCH, based near Chicago, offers an online "financial planning toolkit," filled with background on a host of topics, as well as interactive tools. It's at www.finance.cch.com/welcome.asp.

Two comprehensive sites filled with calculators – everything from "how much home can I afford?" to comparisons of different IRAs or college-savings accounts – are Financial Calculators (www.fincalc.com) and KJE Computer Solutions (www.dinkytown.net).

These companies also provide calculators for use on other websites, which explains why you may see familiar-looking tools if you browse a lot of financial sites.

A final note of caution. The more complicated the issue, the less you should rely on a simple calculator for decisionmaking.

Reckoning the amount of money to save for retirement is a case in point. Many online worksheets deliver a guideline after asking just a few questions. But developing a long-term financial plan, including retirement options, may call for a more sophisticated consideration of your individual needs.

It pays to know when to use a tool, and when to enlist some higher-powered help.