Net Worth Calculator
401k
Account Type
Roth
Traditional
$12,000/yr
Exceeds 2026 limit of $23,500/yr — capped
$3,000/yr
IRA
Account Type
Roth
Traditional
Exceeds 2026 limit of $7,000/yr — capped
Projection
Steady growth
Market simulation
Market Simulation Model
Simulates monthly portfolio movements using Geometric Brownian Motion (GBM) —
the industry-standard model for asset prices.
Each month the portfolio changes by:
exp((μ − σ²/2)·dt + σ·√dt·Z)
where μ is your return rate, σ = 16% (historical S&P 500 volatility), dt = 1/12, and Z is a random standard normal draw. Expected long-run outcome matches steady growth, but paths swing — as in real markets.
Each month the portfolio changes by:
exp((μ − σ²/2)·dt + σ·√dt·Z)
where μ is your return rate, σ = 16% (historical S&P 500 volatility), dt = 1/12, and Z is a random standard normal draw. Expected long-run outcome matches steady growth, but paths swing — as in real markets.
Portfolio Value
—
After-tax at retirement
Total Contributed
—
You + employer (all accounts)
Your Profile
Both Roth and Traditional accounts grow identically — the difference is when you pay tax.
Roth: contribute after-tax dollars, withdraw tax-free.
Traditional: defer taxes now, pay at your retirement bracket.
Choose whichever rate you expect to be lower.
2026 IRS limits: 401k employee $23,500/yr · 401k total (employee + employer) $70,000/yr · IRA $7,000/yr.
Employer match is capped so combined contributions stay within the $70,000 415 limit.
Limits are projected to grow ~2.5%/yr (inflation-adjusted in $500 steps, matching historical IRS adjustments).
Roth IRA income phaseout begins at $150k (single) / $236k (MFJ).
Traditional IRA deductibility limits may apply.