Retirement tool · runs in your browser

Retirement Savings Projector

Estimate how your 401(k) or IRA balance could grow over time based on your current savings, monthly contributions, and expected annual return rate.

$610K
$500/mo at 7% over 30yr (compounding)
70%+
Of a 30yr balance from compounding alone

This retirement savings projector estimates 401(k)/IRA growth from your current balance, monthly contributions, and expected annual return. For example, $500/month at 7% annual return over 30 years grows to about $610,000, even though only $180,000 was contributed, roughly 70% of the final balance is compound growth, not contributions. Enter your own numbers for a personalized projection.

Your 401(k), IRA, or other retirement account balance today.

Your own contributions plus any employer match, combined.

Before inflation, applied uniformly across the full projection period.

The full accumulation period this projection covers, in monthly compounding steps.

How this works

This tool uses standard compound interest projections. It calculates the future value of your current balance growing at your selected return rate, plus the future value of monthly contributions (an annuity) over your chosen time horizon. The formula accounts for monthly compounding, which more closely mirrors how 401(k) and IRA investments actually accrue.

The projection is a simple estimate and does not account for inflation, taxes, fees, or changes in contribution amounts over time. Real returns will vary year to year. See the methodology page for how PlainRetire handles data more broadly.

Key assumptions

  • Returns are compounded monthly at a consistent annual rate
  • Contributions remain constant (no inflation adjustments)
  • No account fees, fund expense ratios, or taxes are deducted
  • Employer matching contributions are not included, add them to your monthly figure

Frequently asked questions

How does compound interest affect retirement savings?

Compound interest means you earn returns on both your original contributions and on previously earned interest. Over a 30-year career, compounding can account for over 60% of your total retirement balance. For example, $500/month at 7% annual return grows to approximately $610,000 over 30 years, even though you only contributed $180,000, roughly 70% of the final balance is compounding, not contributions.

What is a realistic annual return rate for retirement projections?

Historically, a diversified portfolio of 60% stocks and 40% bonds has returned approximately 7-8% annually before inflation (about 4.5-5.5% after inflation). The S&P 500 has averaged roughly 10% nominal returns over the past 50 years. Your actual return depends on your asset allocation, investment fees, and market conditions.

How much should I contribute to my 401(k) each month?

Financial advisors generally recommend saving 10-15% of gross income for retirement. At minimum, contribute enough to capture any employer match, typically 3-6% of salary. Fidelity suggests having 1x your salary saved by age 30, 3x by 40, 6x by 50, and 8x by 60.

Sources

Return rate benchmarks from ICI (Investment Company Institute) and Vanguard historical data. Savings targets from Fidelity retirement planning guidelines. This tool provides estimates only and is not financial advice.

This calculator runs entirely in your browser using the formulas and assumptions described on this page; it does not read from or write to PlainRetire's plan database. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.