401(k) inputs
Useful for simple retirement balance projections with regular contributions.
Essential Calculator
401(k) Calculator
Use this 401(k) calculator to estimate retirement growth from current savings, ongoing contributions, and return assumptions.
How to use this page
- Enter your current balance, monthly contribution, annual return, and years until retirement.
- Use the chart to compare savings discipline and time horizon effects.
- Run conservative and optimistic return scenarios before anchoring on one outcome.
Results
Ending balance$1,582,503
Annual savings$12,000
Years to retire27
Y27$1,582,503
What this calculator helps you see
A 401(k) calculator is most useful when it makes the relationship between time, contributions, and long-term growth obvious.
When to use this calculator
Check whether current savings pace is enough
This is useful when you want a quick sense of how your current contribution path could translate into a future balance.
Compare contribution increases
Even a modest monthly increase can have a meaningful long-term effect when years of growth remain.
Formula
Retirement balance = current savings growth + future contribution growth
The calculator uses monthly compounding and recurring contributions to estimate how a workplace retirement plan could grow over time.
Worked example
Starting with a meaningful 401(k) balance and contributing steadily over multiple decades can produce a much larger end result than contributions alone would imply.
| Item | Value |
|---|---|
| Current balance | $95,000 |
| Monthly contribution | $1,000 |
| Return assumption | 7% |
| Years until retirement | 27 years |
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Before you decide
- Outputs are estimates and should be reviewed against lender or plan-specific terms.
- Inputs are intentionally transparent so assumptions are easy to audit.
- Rates, fees, taxes, and account terms can change the final result.
Page details
- Updated April 15, 2026
- For assumptions and general guidance, see Methodology.
- For how explanatory content is written, see Editorial Policy.
Common 401(k) levers
| Change | Potential effect | Reason |
|---|---|---|
| Increase contribution | High | More capital compounds over time |
| Start earlier | High | Time magnifies growth |
| Lower return assumption | Moderate | Useful for more conservative planning |
Questions and answers
Does this include employer match?
Not separately. You can add expected match by increasing the contribution input if you want a rough estimate.
Should I use a conservative return estimate?
It is usually smart to compare a range of outcomes, including a conservative case, instead of relying on one number.