Roth or traditional? The accounts are mirror images: a traditional 401(k) or IRA gives you a tax break now and is taxed when you withdraw; a Roth is funded with after-tax money now and comes out tax-free later. The winner depends almost entirely on your tax rate today versus in retirement.
The one rule that decides it
If your tax rate will be higher in retirement than it is now, Roth wins — you pay tax at today's lower rate and skip it later. If your rate will be lower in retirement, traditional wins — you deduct at today's higher rate and pay less on withdrawal. If the rates are identical, the after-tax result is the same.
Run your own numbers with the Roth vs. Traditional Calculator, which compares the after-tax value of each given your contribution, time horizon, and tax rates.
Who Roth usually suits
- Younger or lower-income savers who expect to earn (and be taxed) more later.
- Anyone who values tax-free flexibility and wants to avoid required minimum distributions.
- Savers who can afford to contribute the same dollar amount even without the upfront deduction.
Who traditional usually suits
- High earners in a peak tax bracket now who expect a lower bracket in retirement.
- Savers who want the upfront deduction to free up cash to invest elsewhere.
Don't forget the match and the long game
Whatever you choose, capture your full employer match first — it's an instant return. Then let compounding work: see how decades of growth stack up with the Retirement / 401(k) Calculator and the Compound Interest Calculator. Many savers split the difference and hold some of each, which hedges against not knowing future tax rates.