Roth vs Traditional 401(k) on $100k income? (single)
Aisha, 35, in Minneapolis, MN
exampleSingle, no kids · $100k/yr household income
They're maxing their 401(k) in Minneapolis and unsure whether Roth or traditional is quietly costing them.
Aisha is maxing her 401(k) in Minneapolis and doing something most people would call responsible. But the wrong account type could quietly cost her $348,000 by retirement.
The setup
Age
35
Household income
$100,000/yr
Household
Single earner
Liquid savings
$44,000
Retirement savings
$132,000
Investing return
7%/yr
Lean Traditional, your 22% rate drops to ~5% in retirement
22% → 5%
Rate drops 17% in retirement
Rate Now
22%
Rate Retired
5%
Best Strategy
All Trad
NW Diff
+$348k
The math is blunt: Aisha's contributions go in at a 22% federal rate today, but the engine projects her effective rate in retirement at roughly 5%. Paying 22% now to avoid 5% later isn't tax efficiency, it's the opposite. Shifting entirely to Traditional nets her an additional $348,000 in projected net worth, because every dollar deducted today saves 22 cents that then compounds for decades.
Your current effective rate of ~22% (engine-computed) drops to ~5% in retirement. Traditional saves taxes now when your rate is highest. The All Trad strategy produces +$348k more at retirement.
| Scenario | Strategy | Retire NW | Lifetime Taxes | Retire SWR/mo | Coverage |
|---|---|---|---|---|---|
| All Trad | 100% Traditional | $7,565,358 ($3.1M in today's dollars) | $3.9M | $25,218 | 25 yrs |
| Current | Current mix | $7,217,764 ($3.0M in today's dollars) | $3.1M | $24,059 | 25 yrs |
| 50/50 | 50/50 Split | $7,163,267 ($3.0M in today's dollars) | $3.0M | $23,878 | 25 yrs |
| Roth 70% | Tilt Roth (70%) | $6,924,365 ($2.9M in today's dollars) | $2.5M | $23,081 | 25 yrs |
| All Roth | 100% Roth | $6,712,664 ($2.8M in today's dollars) | $2.1M | $22,376 | 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 own rate gap might be narrower or wider than Aisha's, and the only way to know which account is actually costing you is to model your specific numbers.
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Get my verdict →Frequently asked
Roth or traditional 401(k) for a single household earning $100k?
Lean Traditional, your 22% rate drops to ~5% in retirement
Rate drops 17% in retirement
22% → 5%, 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.