401(k) retirement calculator
See where your 401(k) could take you.
Model salary-based contributions across 5,000 potential market paths—not one perfectly smooth rate of return.
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Your Projected 401(k) Balance
Enter your information to calculate a range.
How the Range Changes Over Time
Shaded areas contain the middle 80% and 50% of outcomes.
Simulated rangeSmooth return
Traditional smooth projection—
Total projected contributions—
Employer contributions · Pre-tax—
Why the Range Matters
An average return is not an average experience.
Markets move unevenly
A 7% assumption does not mean investments earn 7% each year. Actual results can move sharply above or below the average.
The order matters
When you add or withdraw money, experiencing a difficult market early versus late can produce a very different ending value.
Plans need room
A range shows the uncertainty around a goal and helps you focus on what you can control: time, savings, costs, and risk.
Methodology
Transparent assumptions, not a prediction.
This calculator generates 5,000 hypothetical monthly return paths using the expected return and volatility shown in Advanced assumptions. General-investing contributions are added monthly and increase by the dollar amount entered each year until the stopping year selected in that calculator. In the 401(k) calculator, the selected salary percentage is converted into an annual employee contribution and spread evenly throughout each year. The annual contribution increase raises that percentage by the number of percentage points entered each year, stopping automatically at a 15% contribution rate. A starting contribution rate above 15% is left unchanged. If selected, employer contributions use either the Safe Harbor formula shown or the custom match rate and salary limit entered. Salary increases independently using the annual salary increase entered. Investment costs are deducted throughout the projection. When inflation is selected, balances and contribution totals are converted to today’s dollars using the inflation rate entered.
The calculator treats the contribution percentage entered as a gross payroll contribution and does not estimate taxes or take-home pay. Increasing a contribution may reduce take-home pay; the actual effect depends on whether contributions are Roth or pre-tax, federal and state tax rules, and individual payroll deductions. Employee contributions are capped at $24,500 before age 50 and $32,500 beginning at age 50. These 2026 limits are used throughout the projection; actual future IRS limits may differ. View the IRS 2026 limits.
The preset assumptions are illustrative and are not forecasts for any specific investment or portfolio. Results do not apply the special higher catch-up limit for ages 60–63, the combined employee-and-employer plan limit, vesting schedules, mandatory Roth catch-up rules, or other plan-specific rules. Unless inflation is selected, projected balances and contributions are shown in future dollars.
Important: All outcomes are hypothetical. Results may vary with each calculation and over time. Simulations cannot predict future performance, actual returns may fall outside the displayed range, and investing involves risk, including loss of principal.
Questions, answered
What this calculator can—and cannot—tell you.
Why is the average outcome different from the smooth projection?
The average-outcome card represents the 50th percentile, or middle simulated result. Volatility reduces compound growth over time. The smooth projection applies one identical return every month, while the simulation allows returns to vary.
How are the projections calculated?
For each month, the calculator draws a return from a lognormal distribution calibrated to the selected annual expected return and volatility. The balance then follows: new balance = prior balance × monthly market factor × monthly cost factor + monthly contribution. This process is repeated across 5,000 paths. The displayed Lower, Average, and Favorable outcomes are the 10th, 50th, and 90th percentiles. When inflation is selected, each value is divided by (1 + inflation rate)years to express it in today’s dollars.
Is the 10th percentile a worst-case result?
No. About 10% of simulated outcomes finish below it, and actual markets can produce results outside the simulation. It is a planning reference, not a guarantee or floor.
Does a higher-risk approach always create more wealth?
No. A higher expected return may raise the middle outcome, but greater volatility also widens the range and increases the possibility of disappointing results.
How does the 401(k) calculator determine my contribution?
It multiplies your annual salary by your selected contribution percentage. The per-paycheck figure divides that annual amount by your chosen number of pay periods, while the projection spreads the same annual total evenly throughout the year. Each year, salary changes by the annual salary increase entered and the contribution rate rises by the annual contribution increase entered. Automatic contribution-rate increases stop at 15%.
How is the employer match calculated?
Safe Harbor matches 100% of the first 3% you contribute and 50% of the next 2%, for a maximum employer contribution equal to 4% of salary when you contribute at least 5%. With Custom match, you enter both the percentage of your contribution the employer matches and the salary percentage where the match stops. For example, a 50% match up to 6% of salary produces a maximum employer contribution of 3% of salary. Employer contributions are always treated as pre-tax.
How could increasing my contribution affect take-home pay?
Increasing your contribution generally reduces take-home pay, but not always dollar for dollar. The actual change depends on whether your plan contribution is Roth or pre-tax, applicable federal and state tax rules, and other payroll deductions. This calculator does not estimate those effects.
How are annual contribution limits handled?
The calculator caps employee contributions at $24,500 before age 50 and $32,500 beginning at age 50. These 2026 limits remain fixed throughout the projection. The higher catch-up available at ages 60–63, future IRS limit changes, and other plan-specific limits are not currently modeled.