Compare "Pre-Tax" 401(k) Easy to "Post-Tax" Roth 401(k) Easy

Traditional "Pre-Tax" 401(k) Contributions Roth "After-Tax" 401(k) Contributions
When you will pay taxes on your contributions You pay the tax upon withdrawal. Contributions are tax-deferred, so current taxes are reduced. You pay regular income tax on your contributions before the money goes into your account. Current taxes are not reduced.
When you will pay taxes on any investment earnings You pay taxes on the full amount of any distribution, including earnings, at ordinary income tax rates in effect upon withdrawal. Your contributions have already been taxed, so there is no tax on them and no taxes on any earnings if you take a qualified distribution.
Qualified distribution rules* Contributions and any earnings remain in account until age 591/2 or a separation from service that qualifies for retirement distributions. Withdrawals are subject to current ordinary income tax at withdrawal (and a 10% tax penalty may apply before age 591/2) unless the tax deferral is continued. Contributions and earnings are distributed tax-free if they meet the requirements of a qualified distribution; earnings in a non-qualified distribution are subject to current ordinary income tax (and a 10% tax penalty may apply before age 591/2) unless the tax deferral is continued.
Impact of contributions on take-home pay Since contributions are pre-tax, your current income tax is reduced and each $1 contributed reduces your take-home pay by less than $1. Because you pay current taxes on your contributions, take-home pay is reduced dollar for dollar by your contributions.
Rollovers from your account You may roll over your account balance upon termination to a traditional IRA, a 401(k) plan or another qualified employer-sponsored plan. You may roll over your account balance upon termination to a Roth IRA or another Roth 401(k) or Roth 403(b) account in a qualified employer plan.

Note: For purposes of the 5-year rule for qualified distributions, the date of the initial contribution to a Roth IRA governs.
Taxes on employer match, if applicable Employer matching contributions are made on a pre-tax basis; contributions and any earnings are taxable upon withdrawal. Same. The employer match is not treated as a Roth contribution.
Required minimum distributions You must begin required minimum distributions by April 1 of the year following the year in which you reach age 701/2 or at retirement, if later. You must begin required minimum distributions by April 1 of the year following the year in which you reach age 701/2 or at retirement, if later.
Loan and hardship Account balances are available for 401(k) loans and hardship withdrawal if the plan allows. Contributions are available for 401(k) loans and hardship withdrawal if the plan allows.

*For purposes of qualified distributions, disability must meet the definition stated in Internal Revenue Code Section 72(m) (7).