401(k) Calculator

What is a 401(k) Calculator?

A 401(k) calculator projects what your workplace retirement account could be worth when you stop working. By combining your current balance, your contributions, employer matching, and an assumed annual return, a 401k calculator simulates compound growth year by year — so you can see whether you are on track for the retirement you want.

Employer matching is what makes a 401(k) uniquely powerful: for every dollar you contribute, up to a limit, your employer adds money on top.

How to Use

1. Enter your current age and desired retirement age.
2. Input your existing 401(k) balance and annual salary.
3. Set your personal contribution percentage.
4. Enter your employer match percentage and the salary limit it applies to.
5. Provide an estimated annual investment return.
6. Click Calculate to see your projected retirement balance.

How the 401k Calculator Projects Your Balance

The calculator simulates your account one year at a time: each year's contributions are added to the balance, then the whole amount grows by the annual return:

New Balance = (Old Balance + Employee Contribution + Employer Match) × (1 + Annual Return)

Repeated until retirement, this equals the future value of your savings plus an annuity:

FV = B × (1 + r)^n + C × [((1 + r)^n − 1) ÷ r] × (1 + r)

• B — your current 401(k) balance
• C — total new money added each year (your contribution plus the match)
• r — annual return as a decimal (7% = 0.07)
• n — years until retirement
• The final × (1 + r) reflects start-of-year deposits, as this calculator assumes.

How the Employer Match Is Calculated

A typical match is "50% of the first 6% of salary": the match rate (50%) means the employer adds 50 cents per dollar you contribute, and the match limit (6%) is the slice of pay eligible. On a $75,000 salary, 6% means you save $4,500 and the employer adds $2,250 — 3% of salary. Above 6% the match stays capped at $2,250; at 3% you get only $1,125 and leave the rest unclaimed.

Worked Example

You are 30, earn $75,000 a year, contribute 6% with a 50% employer match on the first 6%, have $20,000 saved, expect a 7% annual return, and retire at 65 — 35 years of growth:

• Each year you contribute $4,500 and your employer adds $2,250 — $6,750 of new money.
• Year one: ($20,000 + $6,750) × 1.07 = $28,622.50. Year two: $37,848.58.
• After 35 years, the projected balance is $1,211,947.48.

Of that, you contributed $157,500 and your employer added $78,750 ($236,250 together). The remaining $955,697.48 — nearly 79% of the final balance — is pure investment growth.

Projected Balance by Starting Age

Same assumptions as the worked example, varying only the starting age (figures rounded to the nearest dollar):

Starting at 25 instead of 35 more than doubles the final balance, though you contribute only $45,000 more yourself — compound interest does the heavy lifting.

Why the Employer Match Is Free Money

A 50% match is an instant, guaranteed 50% return on the matched dollars — before any market growth. Turning it down means declining part of your pay.

The cost compounds: contributing only 3% when the plan matches the first 6% forfeits $1,125 a year on a $75,000 salary — $39,375 over 35 years, plus lost growth. In the worked example, 3% instead of 6% cuts the projected balance from $1,211,947 to about $712,740 — nearly half a million dollars less.

Traditional vs. Roth 401(k)

Traditional 401(k) contributions are pre-tax: they lower today's taxable income, and withdrawals in retirement are taxed as ordinary income. Roth 401(k) contributions are after-tax, but qualified withdrawals — including decades of growth — are generally tax-free. Many plans offer both.

Rule of thumb: expect a higher tax bracket in retirement? Roth may win; lower? Traditional. The calculator shows pre-tax growth either way — a Roth projection is close to what you keep, while a traditional balance is taxed on withdrawal. Compare the IRA side with the Roth IRA calculator.

Understanding Vesting Schedules

Your own contributions are always 100% yours. Employer match dollars may vest on a schedule:

• Immediate — yours as soon as deposited.
• Cliff — 0% until a set anniversary (say, three years), then 100% at once.
• Graded — ownership builds gradually, such as 20% per year over five years.

Leave before you are fully vested and the unvested match is forfeited; this calculator projects the full match.

Contribution Limits Change Every Year

The IRS caps how much you can defer into a 401(k) each year and adjusts the ceiling annually for inflation, so any dollar figure you memorize can go stale. Workers 50 and older can add catch-up contributions, and a separate higher cap covers total additions including employer money.

Check the current IRS figures or your plan documents each year, and revisit your contribution percentage when your salary changes.

Frequently Asked Questions