401(k) Calculator Formula & How It Works
- 2025 contribution limit: $23,500 ($31,000 if age 50+)
- Common employer match: 50–100% up to 3–6% of salary
- Tax benefit: traditional 401k reduces taxable income now
- FV = (Employee + Employer Contributions) × [(1+r)ⁿ − 1] / r
A 401(k) is a tax-advantaged retirement account. Traditional 401(k) reduces your taxable income now; Roth 401(k) provides tax-free withdrawals in retirement. Employer match is free money — always contribute at least enough to capture the full match. Compound growth tax-deferred over 30+ years is the most powerful wealth-building tool available.