The information you get from Google searches isn't always as reliable as it sounds, but when it comes to simple math, you can bet the search engine is giving you more accurate information. Now Google is turning things up a notch by tossing a calculator widget into your search results to help plan out your mortgage and other loans.
To get the loan widget to appear, search for terms along the lines of "interest," "loan," or "mortgage" calculator. The resulting widget lets you key in a total amount, an interest rate, and a length of time. Google will then give you the total cost you can expect to pay when everything is said and done. The widget works on desktops and mobile devices alike.
The widget saves users from having to hit up one of the many financial websites that offer their own methods of calculating mortgage. It only supports periods of 10 to 40 years, which limits the type of loans you can consider calculating (hopefully it isn't taking you that long to pay off a new car).
Unfortunately the calculator doesn't appear in response to questions such as "What is the total cost of a 20 year loan for $240,000 at a 3.9% interest rate?" For the time being, you will have to enter everything manually.
- Source Engine Land