Roth vs Traditional 401(k) on $100k income? (married)
Most married couples earning $100k assume Roth is the safe, smart default — but for you, that assumption could cost $381,000 by retirement.
The setup
Age
35
Household income
$100,000/yr
Household
Married, dual income
Liquid savings
$44,000
Retirement savings
$132,000
Investing return
7%/yr
Lean Traditional — your 18% rate drops to ~11% in retirement
18% → 11%
Rate drops 7% in retirement
Rate Now
18%
Rate Retired
11%
Best Strategy
All Trad
NW Diff
+$381k
The math is clear: you're paying an 18% marginal rate today, and the engine projects you'll pay only 11% in retirement — a 7-point spread that makes pre-tax Traditional contributions the dominant play. Going all Traditional instead of all Roth produces a $381k difference in net worth, not because of market magic, but purely because of when you hand money to the IRS.
Your current effective rate of ~18% (engine-computed) drops to ~11% in retirement. Traditional saves taxes now when your rate is highest. The All Trad strategy produces +$381k more at retirement.
| Scenario | Strategy | Retire NW | Lifetime Taxes | Retire SWR/mo | Coverage |
|---|---|---|---|---|---|
| All Trad | 100% Traditional | $6,412,360 ($2.6M in today's dollars) | $2.8M | $21,375 | 25 yrs |
| Current | Current mix | $6,031,728 ($2.5M in today's dollars) | $2.0M | $20,106 | 25 yrs |
| 50/50 | 50/50 Split | $6,234,885 ($2.6M in today's dollars) | $2.3M | $20,783 | 25 yrs |
| Roth 70% | Tilt Roth (70%) | $6,110,079 ($2.5M in today's dollars) | $2.0M | $20,367 | 25 yrs |
| All Roth | 100% Roth | $6,013,168 ($2.5M in today's dollars) | $1.9M | $20,044 | 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 rate spread is the lever — plug in your actual numbers to see exactly how much your Roth default is costing you.
Model your own version — free
Your real answer depends on your full picture. Build it in under a minute.
Get my verdict →Frequently asked
Roth or traditional 401(k) for a married household earning $100k?
Lean Traditional — your 18% rate drops to ~11% in retirement
Rate drops 7% in retirement
18% → 11% — 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.
Related scenarios
Related guides
For educational purposes only — not financial advice.