401k Calculator

401(k) Calculator

Estimate your projected 401(k) balance, contributions, employer match, investment growth, and illustrative monthly retirement income in one clear dashboard.

Runs locally in your browser. No sign-up. No personal data stored.

01Your assumptions

Enter your 401(k) details

$
$
%

The percent of salary you contribute each year.

%

Example: 50% means your employer contributes 50 cents for each eligible dollar.

%

The salary percent eligible for employer matching.

%

A hypothetical annual investment return before retirement.

%

Used to grow salary before calculating each future year's contribution and match.

Educational estimate only.

This calculator does not provide financial, investment, tax, or legal advice.

Results are hypothetical and not guaranteed.

02Projection table

Balance over time

Year-by-year estimate based on the current inputs.

03Plain-English method

401(k) formula and assumptions

This calculator projects one year at a time. For each projected year, salary is increased first, then employee contributions and employer match are added after applying the annual return assumption to the existing balance.

For each projected year:

salary = salary × (1 + salary increase) employee contribution = salary × employee contribution percent eligible match percent = min(employee contribution percent, match limit percent) employer match = salary × eligible match percent × employer match percent balance = balance × (1 + annual return) + employee contribution + employer match

The final projected balance equals the ending balance after all projected years. Investment growth is calculated as projected balance minus starting balance, user contributions, and employer match. Monthly retirement income is a simple illustration using projected balance × 0.04 ÷ 12.

04Quick guide

How to use the 401k Calculator

1

Enter age and retirement age

The difference between these ages determines how many years are projected.

2

Add balance and salary

Your current 401(k) balance is the starting point. Salary is grown annually using your salary increase assumption.

3

Set contribution and match

Employee contribution, employer match, and match limit determine how much new money is added each year.

4

Compare scenarios

Adjust return, salary growth, and contribution assumptions to see how the projection changes.

04.1Input explanations

What each 401(k) input means

Employee contribution

The percent of salary you contribute to your 401(k). This estimate does not apply IRS annual contribution limits.

Employer match

The portion of eligible employee contributions your employer adds. A 50% match means $0.50 per eligible $1.00 contributed.

Match limit

The maximum salary percentage eligible for matching. If you contribute above the match limit, the extra contribution is not matched in this model.

Annual return

A hypothetical average annual return. Real markets do not move in a smooth line and may be higher or lower.

Salary increase

The assumed annual salary growth rate used before calculating each future year's contribution and employer match.

05Questions

401k Calculator FAQ

What does this 401k Calculator estimate?

It estimates your projected 401(k) balance, employee contributions, employer match, investment growth, illustrative monthly retirement income, and a balance-over-time table.

Does the calculator include taxes, fees, or IRS contribution limits?

No. The estimate is simplified and does not model taxes, plan fees, vesting, loans, withdrawals, required minimum distributions, or annual IRS limits.

How does the employer match formula work?

The calculator uses the lesser of your employee contribution percent and the match limit percent, then multiplies that eligible amount by the employer match percent.

Why does salary increase affect the projection?

Because contributions and employer match are calculated as percentages of salary, a higher future salary can increase the dollar amount contributed in later years.

Is the monthly retirement income result a guarantee?

No. It is only an illustrative estimate based on a 4% annual withdrawal assumption divided by 12. Actual retirement income depends on many personal and market factors.