AARP Retirement Planning Calculator "The calculator will help you figure out where you are now and what you will need to save to meet your retirement needs."
choosetosave.org's "Ballpark E$timator" Gives a quick estimate of how much you need to save for retirement. Note: Choose to Save is a program of the Employee Benefit Research Institute's Education and Research Fund.
Fidelity Investment's "My Plan Snapshot" This clever little interactive exercise gives some broad investment scenarios for replacing 85% of your pre-retirement income.
FIRECalc: A different kind of retirement calculator This outstanding calculator shows you how your portfolio would perform using historical market data going back to 1871. It can also incorporate information about your expect Social Security benefits and/or pensions. And it will factor in your inflation expectations.
Motley Fool Retirement Calculators Here you'll find over a dozen calculators, each designed to answer a frequently asked retirement planning question: Am I saving enough? What if I underestimate my expenses? How much of an effect can inflation have? and many more.
Nationwide "RetirAbility Check" Features an "8 minute" questionniare to determine your "R-Score." This interactive questionniare was developed for Nationwide Insurance by the Center for Retirement Research at Boston College.
Quicken Retirement Planner An online version of the Quicken software retirement planner. Requires a login account, available to those who have purchased Quicken software.
Consumption Smoothing" Financial Calculator
ESPlanner This product is in a class by itself. Traditional calculators ask you to estimate the income you'll need in retirement. In contrast, ESPlanner (Economic Security Planner) helps you determine your highest sustainable living standard and the savings and life insurance needed to maintain that standard. The software implements the concept of "consumption smoothing" — an economic principle of calculating and maintaining your sustainable lifetime standard of living without belt-tightening in retirement. The basic version costs $149, with an annual fee for updates.