Introduction
A Roth 401(k) lets you pay taxes now so your money grows tax-free. A Traditional 401(k) lets you skip taxes now but pay them later when you withdraw. Which one leaves you with more money at retirement? The answer depends on your tax rates, how much you contribute, and how long your money has to grow.
This Roth 401(k) calculator compares both options side by side. Enter your age, income, contribution amount, and tax rates. The tool then shows you the after-tax value of each account at retirement, including employer match and reinvested tax savings. It also finds the break-even tax rate — the exact point where one option beats the other.
Use this calculator to make a clear, informed choice about where to put your retirement savings. If you are also evaluating a standard pre-tax plan, try our 401k calculator for a focused projection.
How to Use Our Roth 401(k) Calculator
Enter your age, income, tax rates, and savings details below. The calculator will show you whether a Roth 401(k) or a Traditional 401(k) gives you more money after taxes in retirement.
Current Age — Enter how old you are right now. Use the slider or type a number.
Retirement Age — Enter the age when you plan to stop working. This must be higher than your current age. If you are exploring early exit strategies, our early retirement calculator can help you set a target date.
Filing Status — Pick how you file your taxes. Choose Single, Married Filing Jointly, Married Filing Separately, or Head of Household.
Annual Contribution Amount — Enter how much of your own money you put into your 401(k) each year. The calculator will warn you if you go over the IRS limit.
Employer Match Percentage — Enter the percent of your contribution that your employer matches. For example, if they match 50 cents for every dollar you put in, type 50.
Employer Match Cap — Enter the most your employer will match, shown as a percent of your salary. For example, 6 means they only match up to 6% of your pay.
Annual Salary — Enter your yearly pay before taxes. This is used to figure out how much employer match you get. If you need to convert an hourly wage, use our hourly to salary calculator.
Current Marginal Federal Tax Rate — Enter the federal tax rate you pay right now on your last dollar of income. Common rates are 12%, 22%, or 24%. Not sure of your bracket? Our tax bracket calculator can help you find it.
Expected Federal Rate at Retirement — Enter the federal tax rate you think you will pay when you retire. Many people expect a lower rate in retirement.
State Income Tax Rate (Current) — Enter your current state income tax rate. If your state has no income tax, type 0. You can check your rate with our state tax calculator.
State Income Tax Rate at Retirement — Enter the state tax rate you expect to pay in retirement. If you plan to move to a no-tax state, type 0.
Expected Annual Rate of Return — Enter the yearly growth rate you expect on your investments. A common estimate for a mixed stock and bond portfolio is 7%. Our investment calculator can help you model different return scenarios.
Inflation Rate — Enter the rate at which you expect prices to rise each year. A typical estimate is 2.5%. You can explore how inflation erodes purchasing power with our inflation calculator.
Show Results In — Choose "Future Dollars" to see the actual dollar amounts at retirement. Choose "Today's Dollars" to see what that money would be worth in today's buying power.
Click Calculate to see your results. Click Reset to go back to the default values.
What Is a Roth 401(k)?
A Roth 401(k) is a retirement savings account offered through your job. You put money into it from your paycheck after you have already paid taxes on it. The big benefit is that when you retire and take the money out, you pay zero taxes on your withdrawals — including all the growth your money earned over the years.
Roth 401(k) vs. Traditional 401(k)
The main difference between a Roth 401(k) and a traditional 401(k) comes down to when you pay taxes. With a traditional 401(k), you skip taxes now but pay them later when you withdraw the money in retirement. With a Roth 401(k), you pay taxes now and withdraw tax-free later.
Neither option is always better. The right choice depends on whether your tax rate will be higher or lower when you retire. If you expect to be in a higher tax bracket in retirement, a Roth 401(k) usually wins. If you expect a lower bracket, a traditional 401(k) often comes out ahead. You can also use our effective tax rate calculator to understand the difference between your marginal and effective rates.
How This Calculator Helps
This Roth 401(k) calculator compares both account types side by side using your age, income, contribution amount, employer match, tax rates, and expected investment returns. It shows you the after-tax value of each option at retirement so you can see which one puts more money in your pocket. It also calculates the break-even tax rate — the exact retirement tax rate where both options are equal. For a broader view of your retirement readiness, pair these results with our retirement calculator.
Employer Match
Many employers match a portion of what you contribute. For example, your employer might put in 50 cents for every dollar you contribute, up to 6% of your salary. This match is free money and goes into both Roth and traditional accounts the same way. Employer match dollars always go into a traditional (pre-tax) bucket, even inside a Roth 401(k), and will be taxed when you withdraw them.
2026 Contribution Limits
The IRS sets a cap on how much you can put into your 401(k) each year. For 2026, the standard limit is $24,500. If you are age 50 or older, you can add an extra $8,000 in catch-up contributions. Under the SECURE 2.0 Act, workers aged 60 to 63 get an even higher catch-up limit of $12,000 on top of the base amount.
Key Things to Know
- Tax-free growth is the biggest advantage of a Roth 401(k). Your earnings grow and compound without ever being taxed.
- No income limits apply to a Roth 401(k), unlike a Roth IRA. Even high earners can contribute.
- You must hold the account for at least 5 years and be at least age 59½ to take qualified tax-free withdrawals. If you need funds earlier, review the rules with our 401(k) early withdrawal calculator.
- Starting in 2024, Roth 401(k) accounts no longer require minimum distributions during your lifetime, thanks to SECURE 2.0.
- Results shown in "today's dollars" adjust for inflation so you can see what your future savings would be worth in terms of current purchasing power.
- If you already have traditional 401(k) or IRA assets, our Roth conversion calculator can show you the cost and benefit of converting them to Roth.
- For a complete picture of your retirement income, consider running your numbers through our Social Security calculator and retirement withdrawal calculator as well.