401K Tool
Explore potential 401(k) retirement outcomes using your current savings, contribution rates, employer matching and expected investment returns. Compare scenarios, review year-by-year balances, assess retirement income and export projections to support informed financial planning.
| Age | Year | Employee | Employer | Growth | Closing balance |
|---|
Illustrative projection only. Assumes constant return, inflation and fees, with periodic deposits. Tax and plan rules can differ; check your plan and financial adviser. 2026 limits are for standard US 401(k) plans, not SIMPLE plans.
Table of Contents
Highlights
- Interactive retirement savings growth charts
- Employer matching and contribution planning
- Age-based contribution limit checks
- Year-by-year projections and scenario comparisons
- Retirement income estimates and CSV export
How 401(k) Tool Works?
The 401(k) Tool projects retirement savings from your current age to your chosen retirement age using your starting balance, salary, employee contribution rate, employer matching terms, expected salary growth and assumed investment return. The saving horizon is the retirement age minus your current age.
Employee contributions are estimated as a portion of salary; the employer match is added according to the matching terms entered. A simplified annual projection can be expressed as:
Here, B is the retirement balance, r is the assumed annual investment return, C is the employee contribution and M is the employer contribution in year t. This equation illustrates contributions added at the end of each year; the tool's actual results may differ if its calculation uses another contribution timing or compounding convention. Under a constant salary-growth assumption, the illustrative annual salary progression is:
S0 is current salary and g is assumed yearly salary growth. To express a future balance in today's purchasing power, a common inflation adjustment is:
Here, i represents assumed inflation and n is the number of years. The tool presents an interactive balance-growth chart, yearly projections, alternative return scenarios and illustrative retirement withdrawals. These views help compare assumptions rather than predict market performance.
| Input | Role in the projection |
|---|---|
| Current balance | Starting savings available to grow |
| Salary and contribution rate | Employee deposits into the plan |
| Employer matching | Additional plan deposits based on matching terms |
| Salary growth and investment return | Assumed changes in contributions and account value |
| Inflation | Illustrative future purchasing-power adjustment |
| Retirement age | Length of the accumulation period |
Practical Use Cases
Employees reviewing contributions: Compare a 6% salary deferral with an 8% deferral to see how additional deposits may affect the projected balance by retirement.
Workers with employer matching: Enter your plan's matching terms and test whether a higher employee contribution could increase employer-funded savings.
Early-career savers: Explore the long-term effect of starting with a modest balance and contributing consistently across several decades.
Mid-career professionals: Combine an existing balance with expected salary increases to assess whether current saving assumptions support a target retirement date.
People considering earlier retirement: Move the intended retirement age forwards or backwards to compare the effect of fewer or more contribution and growth years.
Pre-retirees: Review estimated retirement withdrawals and inflation-adjusted figures to explore possible spending scenarios, without treating them as guaranteed income.
Financial educators: Use the growth chart, yearly projections and alternative return scenarios to illustrate compounding and the uncertainty of investment returns.
Accuracy and Limitations
The 401(k) Tool provides illustrative projections based on the entered balance, salary, contribution and employer matching settings, assumed salary growth, investment returns, inflation and retirement timing. Actual investment returns fluctuate, whereas a constant assumed return or a small set of scenarios cannot capture market volatility, sequence-of-returns risk or the timing of market declines. Actual salary, employment and contribution patterns can also change. Employer matching may depend on vesting, compensation definitions and individual plan rules. IRS contribution limits, catch-up eligibility and tax treatment vary by tax year and personal circumstances, so displayed assumptions should not be treated as confirmation of compliance. Fees, taxes, loans, hardship withdrawals, early-withdrawal penalties, required minimum distributions and the detailed timing of contributions or withdrawals may not be fully reflected. Inflation-adjusted values depend on the selected inflation assumption, and illustrative retirement withdrawals are not guaranteed sustainable income. Verify plan terms and current tax rules before making decisions.
