Retirement Calculators

Start from the goal, then work out the monthly saving

Retirement planning starts with one number: how much to save each month. This page gathers the calculators that answer it from different directions. The Retirement Calculator works backwards from your goal: give it the target, the time horizon, and an assumed return, and it works out the monthly saving the goal needs. The 401K calculator shows how retirement savings grow when contributions and an employer match are part of the picture. The Roth IRA calculator shows tax-free growth of yearly contributions, which matters because the account a dollar sits in changes what that dollar is worth at withdrawal, even when the growth math is the same.

The three calculators form a workflow rather than three separate tools. First use the Retirement Calculator to find the monthly saving your goal needs, because a goal without a monthly number is a wish, not a plan. Then check the 401K calculator to see how much of that monthly number an employer match covers for you, since matched money is the cheapest progress toward the goal. Then check the Roth IRA calculator for the tax-free side of the plan, especially if you expect your tax rate in retirement to be similar to or higher than your rate now. The Retirement Calculator gives the target. The other two show how the accounts you actually hold move you toward it.

Choosing between the accounts is a sequencing question, not a single right answer. Many savers treat an employer match as the first priority, because turning down matched money is the only move in retirement saving that is wrong on its face. After the match, the choice between a 401K and a Roth IRA turns on taxes: a traditional account defers tax to withdrawal, while a Roth account pays tax now and grows tax-free. The Roth versus Traditional guide walks through that trade in detail. What matters most is not picking the perfect account. It is hitting the monthly number the Retirement Calculator produced, in whichever combination of accounts you hold.

Starting early beats saving harder later, and the numbers are stark. Take $20,000 already saved plus $500 a month at 6 percent. Over 35 years that grows to $874,826.18, from $230,000 of contributions. Over 25 years the same plan reaches $435,796.38, from $170,000 of contributions. Waiting 10 years costs $439,029.80 in final value, while saving only $60,000 less in contributions. The missing $379,029.80 is earnings that never had time to compound. If the monthly number your goal needs looks out of reach, an earlier start or a longer horizon usually closes the gap more cheaply than a larger contribution made late.

A retirement plan is not a one-time calculation. Income changes, goals change, and returns vary, so revisit the numbers at least once a year and whenever either changes. Re-run the Retirement Calculator with the new horizon and the balance you actually hold, then check whether the monthly number still fits. A plan that is reviewed yearly survives bad markets and job changes. A plan that is set once and forgotten only looks like a plan until the goal date arrives.