Compare pre-tax and after-tax retirement contributions to see which option saves you more money. The right choice depends on whether your tax rate is higher now or in retirement.
The key difference between a Roth 401(k) and a Traditional 401(k) comes down to when you pay taxes. With a Traditional 401(k), you contribute pre-tax dollars and pay income tax when you withdraw the money in retirement. With a Roth 401(k), you contribute after-tax dollars and withdrawals in retirement are tax-free.
| Metric | Formula |
|---|---|
| Future Value (FV) | PMT × ((1 + r)^n - 1) / r |
| Traditional After-Tax Value | FV × (1 - retirementTaxRate / 100) |
| Roth Value (Tax-Free) | FV (no tax deduction) |
| Traditional Upfront Tax Savings | Annual Contribution × (currentTaxRate / 100) |
| Roth After-Tax Contribution Cost | Annual Contribution × (1 - currentTaxRate / 100) |
| Monthly Retirement Income | After-Tax Value × (0.04 / 12) (4% withdrawal rule) |
Tax diversification means holding retirement savings in accounts with different tax treatments — some pre-tax (Traditional 401k, Traditional IRA) and some after-tax (Roth 401k, Roth IRA). This strategy gives you flexibility in retirement to withdraw from different buckets strategically, helping you manage your taxable income and potentially reduce your overall tax burden.
The single most important factor in choosing between Roth and Traditional is whether your tax rate will be higher or lower in retirement. If you expect to be in a higher bracket later, Roth is usually better (lock in today's lower rate). If you expect a lower bracket, Traditional is usually better (get the deduction now, pay less later). Many high earners contribute to both to hedge their bets.
Employer matching contributions are always made on a pre-tax basis, regardless of whether you choose Roth or Traditional contributions. This means your employer match will be taxed upon withdrawal. However, the match still significantly boosts your overall savings — always contribute enough to get the full match!
The answer depends primarily on your current tax rate versus your expected tax rate in retirement. If you're in a lower tax bracket now than you expect to be in retirement, a Roth 401(k) is likely better — you lock in today's lower rate. If you're in a higher bracket now and expect to be in a lower one in retirement, a Traditional 401(k) typically wins. Many people contribute to both to create tax diversification.
Yes! Many employers allow you to split your contributions between both account types. The combined contribution limit ($23,000 in 2024, plus catch-up for age 50+) applies across both accounts. This can be a great way to diversify your tax situation in retirement.
No. Employer matching contributions do not count toward your personal contribution limit ($23,000 in 2024). However, the total combined limit (employee + employer) is $69,000 in 2024. Additionally, employer match contributions are always made on a pre-tax basis, even if you contribute to a Roth 401(k).
For a Traditional 401(k), all withdrawals are taxed as ordinary income, and Required Minimum Distributions (RMDs) are required beginning at age 73 (as of 2024). For a Roth 401(k), qualified withdrawals are tax-free if you've had the account for at least 5 years and are age 59½ or older. Under the SECURE 2.0 Act, Roth 401(k) RMDs have been eliminated starting in 2024, making Roth 401(k)s even more attractive.
No. Unlike Roth IRAs, Roth 401(k) accounts have no income limits for contributions. High earners can contribute directly to a Roth 401(k) regardless of their income level. This makes Roth 401(k)s an excellent option for high-income earners who want tax-free growth but are phased out of Roth IRA contributions.