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401k Calculator
A 401k calculator projects what your retirement account could be worth on the day you retire. Enter your current balance, how much you and your employer put in each year, and the return you expect, and it shows your projected balance, your total contributions, and how much of the final number comes from investment growth.
0 if your employer offers no match.
| Your current balance grows to | |
| Your contributions grow to | |
| Total paid in (balance + contributions) | |
| Investment growth |
How it works
A 401k grows in two ways at once. The money already in the account compounds year after year, and every new contribution you make starts compounding from the year it goes in. That is why starting early matters so much: money added in your twenties has forty years to grow, while money added in your fifties has only a few.
Your current balance is what is in the account today. Your annual contribution is what you put in each year from your paycheck, before tax in a traditional 401k. The employer match is extra money your employer adds, expressed here as a percentage of your own contribution — a 50% match on a $6,000 contribution adds $3,000 a year. The expected annual return is the average yearly growth of your investments, and years until retirement is how long the money keeps compounding.
This calculator uses annual compounding: each year your balance grows by the return, then that year's contribution is added. The formula is:
where r is the annual return and n is the number of years. The contribution in the formula includes the employer match.
Remember that the result is a projection, not a promise. Real returns bounce around — a 5% average might mean +18% one year and −12% the next — and this calculator smooths that into a steady yearly rate. It also ignores taxes, fees, and inflation. A balance of $500,000 in thirty years will buy less than $500,000 buys today, so treat the number as a planning guide and rerun it with lower returns to see a cautious case.
Worked example
Meet Sarah, 35, in Austin, Texas. She has $25,000 in her 401k, contributes $6,000 a year, gets no employer match, expects a 5% average annual return, and plans to retire in 30 years at 65.
First, her current balance grows on its own: $25,000 × 1.0530. Since 1.0530 is about 4.3219, that comes to $108,048.56. Next, her yearly contributions compound: $6,000 × ((1.0530 − 1) ÷ 0.05) = $6,000 × 66.4388 = $398,633.09. Add them together and her projected balance at retirement is $506,681.64.
She will have paid in $25,000 + ($6,000 × 30) = $205,000 of her own money, so the remaining $301,681.64 is investment growth — more than she contributed. That is the power of compounding over three decades. If her employer matched half her contribution, adding $3,000 a year, her projected balance would jump to about $705,948. Try it in the calculator above and see how much a match is worth over a career.
FAQ
How much should I have in my 401k by retirement?
A common rule of thumb is 10 to 12 times your final salary by age 67, but the right number depends on your spending, Social Security, and other savings. Use this calculator to test different contribution levels and see which target is realistic for you.
Does this 401k calculator include the employer match?
Yes. Enter your employer's match as a percentage of your annual contribution, and the calculator adds it to your yearly contribution before compounding. A 100% match on the first 3% of pay, for example, is free money you should never leave on the table.
What return should I assume for a 401k?
The US stock market has averaged about 7% a year after inflation over the long run, and many planners use 6% to 8% before inflation for a stock-heavy portfolio. This calculator uses the nominal return you enter, so try 5%, 7%, and 9% to see a range of outcomes.
Are 401k withdrawals taxed?
Withdrawals from a traditional 401k are taxed as ordinary income in the year you take them, and withdrawals before age 59 and a half usually face an extra 10% penalty. Roth 401k withdrawals are generally tax-free in retirement if the rules are met. This calculator shows the balance before taxes.