Roth vs Traditional 401(k) on $300k income? (single)

Leah, 35, in Boston, MA

example

Single, no kids · $300k/yr household income

They're maxing their 401(k) in Boston and unsure whether Roth or traditional is quietly costing them.

35, single, $300k/yr. Roth or traditional 401(k)? "Always Roth" isn't always right at this income. Here's the lifetime-tax difference, modeled year by year.

The setup

Age

Household income

$300,000/yr

Household

Single earner

Liquid savings

$132,000

Retirement savings

$396,000

Investing return

7%/yr

SHIFT

Lean Traditional, your 30% rate drops to ~3% in retirement

30% → 3%

Rate drops 27% in retirement

Projected net worth

Today: $723k$103M projected

Rate Now

30%

Rate Retired

Best Strategy

Current

NW Diff

Your current effective rate of ~30% (engine-computed) drops to ~3% in retirement. Traditional saves taxes now when your rate is highest. The Current strategy produces $0 more at retirement.

Scenario	Strategy	Retire NW	Lifetime Taxes	Retire SWR/mo	Coverage
All Trad	100% Traditional	$24,981,641 ($10M in today's dollars)	$11M	$83,272	25 yrs
Current	Current mix	$24,657,632 ($10M in today's dollars)	$10M	$82,192	25 yrs
50/50	50/50 Split	$24,239,806 ($10.0M in today's dollars)	$9.5M	$80,799	25 yrs
Roth 70%	Tilt Roth (70%)	$23,845,221 ($9.8M in today's dollars)	$8.9M	$79,484	25 yrs
All Roth	100% Roth	$23,496,760 ($9.7M in today's dollars)	$8.4M	$78,323	25 yrs

Tax laws change. Roth conversions, RMDs, and state tax changes can shift the calculus. This analysis uses current rates as a starting point.

Your real number depends on your savings, debts, and city. The averages above are a starting point. Model your exact situation and get your verdict.

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Frequently asked

Roth or traditional 401(k) for a single household earning $300k?

Lean Traditional, your 30% rate drops to ~3% in retirement

Rate drops 27% in retirement

30% → 3%, modeled with Rightmont's projection engine for this exact scenario.

How was this calculated?

Rightmont runs your numbers through a year-by-year projection engine (taxes, compounding, Social Security, and your real cashflow) to model the outcome. Model your own version free in under a minute.

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For educational purposes only, not financial advice.