A frequent flyer miles calculator is an online tool that can help rewards program members determine how many points a particular trip is worth. The calculators require the airport code of both the departure location and the destination location. The official websites of the major commercial airlines who offer frequent flyer miles programs, including American Airlines, United Airlines, Delta, Northwest Airlines, US Airways and Continental, may feature similar tools and there are websites that will calculate the milage for travelers as well.

The policies of frequent flyer miles programs, like Delta's SkyMiles, Continental's OnePass or American Airlines' Aadvantage, will vary and websites unaffiliated with the official programs may not provide an exact calculation of miles as they provide estimates. However, most of the online frequent flyer calculators, like MileCalc.com and Fly.Qux.Us, base their calculations on the "great circle distance," which is the same way the majority of major airlines in the United States calculate miles.http://www.webflyer.com/travel/mileage_calculator/http://www.flyertalk.com/forum/delta-skymiles-pre-worldperks-merger/699457-skymiles-calculator-tool.html

Planning a trip's worth in milage points is beneficial to frequent flyer club members since one route may be worth more in points that another. The accrued milage earned by traveling by air can then be redeemed for airline tickets, hotel stays, travel packages, car rentals or other perks offered depending on the program. This page serves as a resource for finding reliable frequent flyer miles calculators online.

Websites like WebFlyer.com allow users to enter their departing airport, destination airport, travel dates, and details related to the milage points given through their program. For specific details, frequent flyer club members should refer to their specific program policy. Online frequent flyer milage calculators will usually allow the traveler to enter any special bonuses they qualify for as well as the actual ticket price paid. Upon clicking 'enter', 'submit' or a similar button, the calculator will update to reflect the actual amount of miles that will be rewarded for such a trip.http://www.webflyer.com/travel/mileage_calculator/