401(k) Growth Calculator
This calculator projects how your 401(k) balance could grow over time based on your contributions, employer match, and expected investment returns. Adjust the inputs to see how small changes today can dramatically affect your retirement nest egg.
How it works
Each year your balance grows by your expected return, then your contributions (plus your employer's match) are added. This repeats for every year until retirement, compounding gains on top of gains.
The math is: new_balance = old_balance × (1 + return) + annual_contributions. We apply the return first, then add your total yearly deposits — your own contribution plus the employer match percentage applied to it.
Compounding is the engine behind retirement wealth. Money invested early has decades to multiply, which is why starting sooner often beats contributing more later.
Tips
Always contribute at least enough to capture your full employer match — it's an instant, guaranteed return on your money.
Even a 1% higher annual return or an extra few years can add tens of thousands to your final balance, so revisit your contribution rate whenever you get a raise.
FAQ
Does this include employer match?
Yes. The employer match percentage is applied to your annual contribution and added to your savings each year, increasing total growth.
What return rate should I use?
Historical diversified stock-and-bond portfolios have averaged roughly 6–8% annually over the long term, but returns vary and are never guaranteed.
Are taxes and inflation included?
No. This is a pre-tax growth estimate and does not adjust for inflation. Traditional 401(k) withdrawals are taxed as income in retirement.