401(k) Calculator

What is a 401(k)?

A 401(k) is an employer-sponsored retirement savings plan that allows you to invest a portion of your paycheck before taxes are taken out. Named after a section of the U.S. Internal Revenue Code, it is one of the most powerful wealth-building tools available to American workers. Your contributions grow tax-deferred — meaning you pay no taxes on the gains until you withdraw the money in retirement, typically after age 59½. Many employers also offer a matching contribution, effectively giving you free money on top of your own savings.

How can a 401(k) calculator help you?

Retirement planning without numbers is just guesswork. A 401(k) calculator shows you exactly how your contributions, employer match, salary growth, and investment returns combine over time to build your nest egg. By adjusting variables like contribution percentage, expected return rate, and retirement age, you can see the real cost of delaying savings — and the powerful impact of even small increases in your contribution rate. Use it to set concrete savings goals aligned with your retirement lifestyle.

How does the 401(k) growth formula work?

The 401(k) balance grows through the future value of a series of contributions (annuity), compounded annually. The core formula used is:

How to use Finzony's 401(k) calculator

Getting your retirement projection takes less than a minute. Follow these steps:

1. Enter your current age and retirement age: The gap between these two numbers is how long compound growth has to work for you.
2. Set your annual salary: This is the base for calculating your contribution amount and employer match.
3. Choose your contribution rate: Enter the percentage of your salary you contribute each pay period. At minimum, match what your employer will match.
4. Add your employer match details: Input your employer's match percentage and the salary cap it applies to (e.g., 50% match on up to 6% of salary).
5. Set expected annual return: Use 6–8% for a diversified portfolio. Be conservative — it's better to be pleasantly surprised.
6. Get your projection: The calculator instantly shows your estimated 401(k) balance at retirement, broken down year by year.

Advantages of a 401(k)

• Tax-Deferred Growth: Your investments grow without being taxed each year. You only pay taxes when you withdraw in retirement, allowing compound growth to work at full power.
• Employer Match = Free Money: Many employers match a portion of your contributions. Contributing at least enough to get the full match is an instant 50–100% return on that money.
• Reduces Taxable Income Now: Traditional 401(k) contributions are pre-tax, lowering your taxable income today. Contributing $10,000 could save $2,200+ in taxes if you're in the 22% bracket.
• Automatic & Disciplined Saving: Contributions are deducted from your paycheck automatically. You never see the money, so you're less tempted to spend it — making saving effortless.