401k Calculator

Quickly estimate how much your 401k could grow with different contributions, employer matches, and years invested.

401k Calculator

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Plan Your Retirement with Our 401k Calculator

Saving for retirement can feel overwhelming, but a 401k is one of the most powerful tools to secure your financial future. Our 401k calculator helps you visualize how your savings grow over time with compound interest, your contributions, and your employer's match.

How the 401k Calculation Works

The formula behind our calculator combines monthly contributions (including employer match) with compound growth:

  • Current Balance: What you’ve already saved.
  • Monthly Contribution: Your payroll deferral into the 401k.
  • Employer Match: The percentage your employer adds to your contributions.
  • Years Until Retirement: How long your money grows.
  • Annual Return: Expected investment growth (historically 5%-8%).

The general growth is calculated as:

Future Value = Current Balance × (1 + r/n)^(nt) + Contributions × [((1 + r/n)^(nt) - 1) / (r/n)]

where:

  • r = annual return rate
  • n = 12 (monthly compounding)
  • t = years

Examples

For example, if you have a $50,000 balance, contribute $500 monthly, get a 50% employer match, and expect 6% annual return for 20 years, your account could grow to over $350,000.

Why Use This Calculator?

Limitations

This tool provides an estimate. Actual returns vary due to market fluctuations and plan fees. Consider using it alongside a loan calculator if you’re balancing debts with savings.

Benefits of a 401k

  • Tax-deferred growth means you pay taxes later.
  • Employer match is essentially free money.
  • Automatic payroll deductions make saving easier.

Start Planning Today

Small adjustments today lead to a huge impact over decades. Use our 401k calculator to explore scenarios, adjust your contributions, and build the future you want.

Frequently Asked Questions

How is a 401k calculated?

A 401k balance grows through your contributions, your employer's match, and compound interest. The typical formula multiplies your existing balance and contributions by monthly compounded growth over the number of years until retirement.

How much should I contribute to my 401k?

Most experts recommend at least 10-15% of your income. This often includes your employer’s contribution. Our calculator lets you see different scenarios.

What is the average 401k balance by age?

According to Vanguard, average balances range from $30,000 for those under 35, to over $200,000 for those near retirement, but medians are often much lower.

Can I rely only on my 401k for retirement?

It’s best to diversify. Consider additional savings like IRAs, brokerage accounts, or even income streams. Use our ROI calculator to compare other investments.

How does an employer match work?

If your employer offers a match, they contribute a percentage (like 50%) of what you put in, up to a cap. This is free money toward your retirement.

References

401k Calculator online tool showing inputs for balance, contribution, employer match, years, expected return with blue calculate button

Written by Creesler

Last updated: 7/1/2025