Roth vs Traditional Retirement Contribution Calculator

Roth vs Traditional IRA and 401(k): Which Is Right for You?

One of the most common questions in retirement planning is whether to contribute to a Roth account or a traditional one. Both types of accounts are designed to help you save for retirement with favorable tax treatment, but they work in opposite ways. The right choice depends largely on your current tax situation and where you expect to be financially when you retire.

A traditional IRA or 401(k) gives you a tax deduction on contributions today. The money you put in reduces your taxable income for the current year, which means you pay less tax now. However, when you withdraw funds in retirement, those withdrawals are taxed as ordinary income. This structure benefits people who are in a higher tax bracket now than they expect to be in retirement.

A Roth IRA or Roth 401(k) works in reverse. You contribute with after-tax dollars, meaning there is no deduction today. In exchange, all qualified withdrawals in retirement are completely tax-free, including the investment growth. This is highly advantageous if you expect your tax rate to be higher in retirement than it is now.

Understanding Future Value and Tax Impact

This calculator assumes a 7% annual growth rate applied to your annual contribution over the number of years you specify. This is a common long-term assumption for a balanced portfolio, though actual returns will vary. Both account types produce the same future value before tax because the underlying investment is identical. The difference shows up at withdrawal time.

For the traditional account, the tax saving you receive today is calculated by multiplying your contribution by your current marginal rate. If you contribute $6,500 at a 22% tax rate, you save $1,430 in taxes this year. However, the full future value is subject to income tax when you withdraw it in retirement. If your retirement bracket is 18%, you keep 82% of the final amount.

For the Roth account, you receive no upfront deduction, but the entire future value is yours tax-free. If your retirement bracket turns out to be higher than your current rate, Roth wins decisively. If your current rate is substantially higher, traditional has the edge. At equal rates, both options are mathematically equivalent in terms of net wealth.

A practical consideration is that Roth accounts also offer more flexibility. You can withdraw your contributions (not earnings) at any time without penalty. Roth accounts are also not subject to required minimum distributions (RMDs) during the account holder's lifetime, unlike traditional accounts which require minimum withdrawals starting at age 73.

Key Factors That Influence the Decision

Beyond the basic tax bracket comparison, several other factors should inform your choice. If you are early in your career and expect your income to grow significantly over time, a Roth account is often the better choice since your tax rate is currently low. If you are in your peak earning years and expect a lower income in retirement, a traditional account may reduce your lifetime tax bill.

Some financial advisors recommend diversifying across both account types to hedge against future tax changes. Holding some money in Roth and some in traditional accounts gives you flexibility in retirement to draw income from whichever source is most tax-efficient in a given year. This strategy is sometimes called tax diversification.

Income limits also apply. Roth IRA contributions are phased out at higher income levels, though high earners can use a backdoor Roth conversion strategy. Traditional IRA deductibility phases out if you are covered by a workplace plan and your income exceeds certain thresholds. Roth 401(k) plans have no income limit, making them accessible to all employees whose employers offer them.

Contribution limits for 2025 are $7,000 for IRAs (plus a $1,000 catch-up contribution if you are 50 or older) and $23,500 for 401(k) plans. These limits apply across both Roth and traditional accounts combined, not separately.

Use this calculator to model your specific numbers, then consult with a financial advisor or tax professional to account for your full financial picture before making a final decision.