401(k) Calculator
Estimate how your current 401(k) balance, employee contributions, employer matching, salary growth and investment returns could affect your retirement savings over time.
Retirement Timeline
Set the period over which the account is projected to grow.
Current Savings & Salary
Contributions & Employer Match
Model employee contributions and a typical employer matching arrangement.
Investment Assumptions
Illustrative projection based on the assumptions entered above.
| Current Age | — |
| Retirement Age | — |
| Years Until Retirement | — |
| Current 401(k) Balance | — |
| Current Annual Salary | — |
| Employee Contribution Rate | — |
| Employer Match | — |
| Employer Match Limit | — |
| Annual Contribution Cap | — |
| Expected Investment Return | — |
| Expected Inflation | — |
Step-by-Step Calculation
What Is a 401(k)?
A 401(k) is an employer-sponsored retirement savings arrangement commonly used in the United States. An employee generally chooses how much of eligible compensation to contribute, and a plan may also provide employer contributions such as a matching contribution. The exact rules depend on the individual plan.
How Does a 401(k) Calculator Work?
This calculator projects the future value of an account by starting with the current balance and then adding estimated employee and employer contributions while applying an assumed investment return month by month.
Salary is increased using the assumed annual salary-growth rate. Because contribution percentages are tied to salary, contributions can increase as the modeled salary increases. An optional annual employee contribution cap can limit the employee contribution used in the projection.
How Employer Matching Works
Employer matching rules vary by plan. A common arrangement matches a percentage of an employee’s contribution up to a specified percentage of salary.
Employee contribution = 6% of salary
Employer match = 50% of eligible contribution
Match limit = 6% of salary
Maximum employer contribution = 6% × 50% = 3% of salary
Check your actual plan documents for eligibility, vesting, matching formulas, compensation definitions, and any limits that apply to you.
Why Employer Matching Can Matter
An employer contribution can increase the amount entering the retirement account without increasing the employee’s own contribution. When those additional contributions remain invested, they may also participate in future compounding.
Why Salary Growth Matters
When contributions are calculated as a percentage of salary, salary increases can raise the dollar amount contributed each year. If the employer match is also linked to salary, the employer contribution can rise as well.
For this reason, a 401(k) projection can change significantly when you compare a flat salary assumption with a growing salary assumption.
Why Compound Growth Matters
Investment returns can compound when gains remain invested. The longer the modeled investment period, the more time earlier contributions have to participate in that compounding. Actual returns, however, fluctuate and may be negative in some periods.
Inflation-Adjusted 401(k) Value
A future account balance is measured in future currency units. Inflation can reduce what that balance can purchase. This calculator therefore also shows an estimate expressed in today’s purchasing power.
This adjustment is a purchasing-power comparison. It does not predict future prices or guarantee the real spending power of the account.
401(k) Calculator Example
Suppose someone is 35 years old, has 50,000 saved, earns 75,000 per year, contributes 6% of salary, and receives a 50% employer match on eligible contributions up to 6% of salary. If the person assumes a 3% annual salary increase and a 7% annual investment return until age 65, the calculator can project the account month by month.
The result will change if you change the contribution rate, employer match, salary growth, investment return, retirement age, inflation, or contribution cap. This makes scenario comparison more useful than treating one projection as a forecast.
Traditional vs. Roth 401(k)
Traditional and Roth 401(k) arrangements can have different tax treatment. In broad terms, traditional contributions are generally made before income tax and withdrawals are generally taxable, while Roth contributions are generally made after tax and qualified withdrawals may receive different tax treatment. Eligibility and tax rules can vary.
This calculator does not estimate taxes, after-tax retirement income, Roth conversion effects, required distributions, or the tax treatment of withdrawals. Use your plan documents and current tax guidance for those questions.
How to Use the 401(k) Calculator
- Enter your current age and desired retirement age.
- Enter your current 401(k) balance and annual salary.
- Enter your employee contribution percentage.
- Enter the employer’s matching percentage and match limit, if applicable.
- Optionally enter an annual employee contribution cap.
- Choose assumptions for salary growth, investment return, and inflation.
- Review the projected balance, contributions, investment growth, and today’s-money value.
- Change one assumption at a time to compare scenarios.
Important Assumptions and Limitations
- The investment return is an assumed average rate and does not represent a guaranteed return.
- The model applies investment growth monthly using an effective monthly rate derived from the annual return assumption.
- Salary growth is modeled smoothly over time and may not match real raises or career changes.
- Employer matching is simplified using the match percentage and salary limit entered by the user.
- The optional contribution cap is a user-entered modeling assumption; actual legal and plan limits can be more complex.
- Investment fees, taxes, withdrawals, loans, vesting schedules, catch-up contributions, plan-specific compensation rules, and asset allocation are not modeled.
- Real investment performance can vary substantially from year to year.
Ways to Strengthen a Retirement Savings Plan
- Review your employer’s matching rules and vesting schedule.
- Consider increasing your contribution rate when your income rises.
- Compare conservative, moderate, and higher-return assumptions rather than relying on one scenario.
- Consider fees and investment diversification when reviewing your plan.
- Keep an emergency fund and manage high-cost debt alongside long-term retirement saving.
- Review the plan periodically as your salary, goals, household situation, and retirement date change.
Frequently Asked Questions
What does a 401(k) calculator estimate?
It estimates how a current balance and future contributions could grow under the assumptions you enter. It is a projection rather than a guarantee.
How is employer matching calculated?
The calculator uses the employer match percentage you enter and limits eligible employee contributions to the employer match limit expressed as a percentage of salary.
What if my employer does not offer a match?
Enter 0% for the employer match. The projection will then exclude employer matching contributions.
What does the annual contribution cap do?
If you enter a positive cap, the employee contribution used in the projection is limited to that annual amount. Leave it blank or enter 0 when you do not want the calculator to apply a cap.
Does the calculator include taxes?
No. It does not calculate income taxes, withdrawal taxes, Roth conversion taxes, or after-tax retirement income.
Does it account for investment fees?
No. Investment fees are not modeled separately. A lower assumed investment return can be used for a simple sensitivity test, but this is not a substitute for modeling actual fees.
Why is the future balance different when I change inflation?
Inflation does not change the nominal projected balance in this calculator. It changes the separate estimate of what that future balance is worth in today’s purchasing power.
Can I use this calculator for a Roth 401(k)?
You can use it for a contribution-growth projection, but the calculator does not model the different tax treatment of Roth and traditional accounts.
Should I treat the projected balance as guaranteed?
No. Market returns, salary changes, contributions, employer matching, fees, taxes, inflation, and personal circumstances can all differ from the assumptions.
How can I compare retirement scenarios?
Run several calculations while changing one major assumption at a time, such as contribution rate, retirement age, investment return, salary growth, or employer match.
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Important: This calculator is provided for general informational and educational purposes only. It does not constitute financial, tax, legal, investment, retirement, or other professional advice. Results depend on assumptions entered by the user and are not guarantees of future investment performance or retirement outcomes. Actual plan rules, contribution limits, taxes, fees, employer matching, inflation, salary changes, withdrawals, and market performance may differ. Consider your individual circumstances and consult a qualified professional when appropriate.