Roth 401(k) vs Traditional 401(k): Which Saves More on Taxes?

How Traditional 401(k) Works

With a Traditional 401(k), your contributions are made with pre-tax dollars. This means every dollar you contribute reduces your current taxable income. If you earn $100,000 and contribute $23,500, your taxable income drops to $76,500, immediately saving you thousands in taxes.

The trade-off: when you withdraw money in retirement (after age 59.5), every dollar is taxed as ordinary income at your then-current tax rate. You are essentially deferring taxes from your high-earning years to your retirement years, betting that your tax rate will be lower then.

For someone in the 24% bracket contributing $23,500, the Traditional 401(k) provides an immediate tax savings of $5,640 in federal income tax. That is money that stays in your paycheck right now. Use our Salary Calculator to see the paycheck impact.

How Roth 401(k) Works

With a Roth 401(k), you contribute after-tax dollars. Your current paycheck is smaller because you do not get a tax deduction, but all qualified withdrawals in retirement are completely tax-free, including all investment gains.

Unlike a Roth IRA, the Roth 401(k) has no income limits. Even if you earn $500,000 a year, you can contribute to a Roth 401(k), making it the only way for high earners to build a substantial Roth retirement balance.

Under SECURE 2.0, Roth 401(k) accounts are no longer subject to Required Minimum Distributions (RMDs) starting in 2024, giving them the same advantage as Roth IRAs for estate planning.

Tax Impact Comparison by Income Level

This table shows the annual tax cost of choosing Roth over Traditional at different income levels, assuming the full $23,500 contribution:

The "paycheck diff" column shows how much less per month you receive by choosing Roth. Use our Take-Home Pay Calculator to model the exact impact on your paycheck.

When Traditional 401(k) Wins

Traditional contributions save more money in these scenarios:

• You are in a high tax bracket now (32%+): The immediate tax savings are substantial, and most retirees withdraw at lower rates
• You will retire to a no-income-tax state: If you work in California (13.3% top rate) but retire to Florida or Texas, you avoid state tax entirely on withdrawals
• You expect lower income in retirement: Most people spend less in retirement. If your retirement withdrawals put you in the 12% or 22% bracket, you save the difference
• You need maximum paycheck now: The pre-tax deduction gives you a bigger paycheck, which matters if you are paying off debt or saving for a home

For tax bracket details, check LevyIO's Tax Bracket Calculator.

When Roth 401(k) Wins

Roth contributions are the better choice when:

• You are early in your career (low bracket): If you are in the 12% bracket, paying 12% tax now to never pay tax on decades of growth is an exceptional deal
• You expect tax rates to rise: If Congress raises rates in the future, your Roth withdrawals are protected at today's lower rates
• You will have a pension or significant Social Security: Other income sources may push your retirement bracket higher than expected
• You want estate planning flexibility: Roth 401(k) accounts pass to heirs tax-free and are no longer subject to RMDs

The Split Strategy: Best of Both Worlds

Many financial advisors recommend splitting contributions between Roth and Traditional to create tax diversification in retirement. For example, contributing 60% Traditional and 40% Roth gives you:

• Tax deductions now to reduce your current bill
• A tax-free pool in retirement for years when you need higher income without bracket creep
• Flexibility to manage taxable income year by year in retirement

This strategy is especially powerful for people in the 22-24% bracket who are unsure where they will land in retirement. Read our 401(k) Contribution Guide for detailed contribution strategies.

2026 Contribution Limits and SECURE 2.0 Changes

The 2026 limits and rules to know:

• Employee limit: $23,500 combined Roth and Traditional
• Age 50+ catch-up: Additional $7,500 ($31,000 total)
• Age 60-63 super catch-up: Additional $11,250 ($34,750 total) under SECURE 2.0
• Total limit (with employer): $70,000 combined employee + employer contributions
• High earner catch-up must be Roth: Under SECURE 2.0, employees earning $145,000+ must make catch-up contributions to Roth only (delayed to 2026)

For more on retirement timelines, see our Retirement Savings by Age benchmarks.

Calculate Your 401(k) Impact

See how Roth vs Traditional contributions change your take-home pay and long-term retirement balance.