401k Retirement Calculator

A 401k retirement calculator answers two questions at once: how much will you have at retirement, and how much income will it give you? The free 401(k) calculator above projects the balance at 65 and turns it into monthly income with the 4% rule, and this page explains both numbers on the default example — a 35-year-old with a $25,000 balance, a $75,000 salary, and a 10% contribution.

On the default example, the balance at 65 is $1,400,662.80. The 4% rule turns that into $56,026.51 a year, or $4,668.88 a month. In today’s dollars, the balance is $577,054.53, which is $1,923.52 a month. The tables below show the 4% rule at four balances, what fees do to the result, and the savings targets by age.

How Retirement Income Is Calculated

The calculator projects your account year by year from your current age to 65: each year it adds your contribution and your employer’s match, grows the balance by your expected return minus fees, and raises your salary by the growth rate you enter. The final balance is the sum of your contributions, the employer’s contributions, and the investment growth. Then the 4% rule turns the balance into income: withdraw 4% of the balance in the first year of retirement and adjust for inflation after that.

On the default example, the balance at 65 is $1,400,662.80. Four percent of that is $56,026.51 a year, which is $4,668.88 a month. Total contributions are $395,538.77 — $304,260.59 of your own money and $91,278.18 from your employer — and investment growth is $980,124.02. The balance in today’s dollars is $577,054.53, or $1,923.52 a month, at 3% inflation. The final salary at 65 is $135,852.12.

Step 1 — Project the balance to 65

Your contributions plus the employer match, grown by the return each year. On the default, the first year adds $7,500.00 of your own money and $2,250.00 of match, for $9,750.00.

Step 2 — Apply the 4% rule

Multiply the balance at 65 by 4% and divide by 12 for the monthly income. On the default, $1,400,662.80 times 4% is $56,026.51 a year, or $4,668.88 a month.

Step 3 — Check the today’s-dollars figure

Inflation shrinks what the money will buy. At 3% inflation, the $1,400,662.80 balance is worth $577,054.53 in today’s dollars, which is $1,923.52 a month under the 4% rule.

Worked Examples: The 4% Rule at Four Balances

Each row is a balance run through the 4% rule: 4% of the balance is the first-year income, divided by 12 for the monthly figure.

The $1,400,662.80 row is the default projection: a 35-year-old with a $25,000 balance, a $75,000 salary, and a 10% contribution. The 4% rule is a rule of thumb, not a guarantee — it assumes the money lasts about 30 years, and it was built on historical stock and bond returns. Social Security and any pension sit on top of this income, so the 4% figure is not your whole retirement income. The today’s-dollars version of the default is $577,054.53, or $1,923.52 a month — the number to compare with your current spending.

How to Use the 401k Retirement Calculator

Start with the numbers on your pay stub and your plan statement. The more of them you enter, the closer the projection lands.

1. Enter your current age. The default is 35. The calculator projects to 65.
2. Enter your current 401(k) balance. The default is $25,000.
3. Enter your annual salary. The default is $75,000.
4. Enter your contribution percentage. The default is 10%. The calculator caps it at the IRS limit and tells you when the cap applies.
5. Pick the employer match. The default is 50% of the first 6% of pay.
6. Enter the expected return, salary growth, fees, and inflation. The defaults are a 7% return, 2% salary growth, no fee, and 3% inflation.
7. Read the balance at 65 and the 4% rule income. The big number is the projected balance; the table shows the income per month and the balance in today’s dollars.

The result updates as you type. Try changing the return from 7% to 6% and watch the balance at 65 fall from $1,400,662.80 to $1,159,551.26, and the 4% rule income fall from $4,668.88 to $3,865.17 a month.

What Fees Do to Your Retirement

Fees are the quietest leak in a retirement account. The table below runs the default example — age 35, $25,000 balance, $75,000 salary, 10% contribution — at a 0%, 0.5% and 1% annual fee, with a 7% return.

A 1% fee costs $241,111.54 over 30 years on the default — more than the $152,130.30 a 5% contributor puts in over the same period. The fee looks small because it is charged on the balance each year, but the balance grows, so the fee grows with it, and the money it takes never compounds. A 1% fee at a 7% return leaves exactly the same balance as a 6% return with no fee: $1,159,551.26 in both cases. Total contributions are $395,538.77 in all three rows, so the whole difference is lost growth. Check the expense ratio on your funds — it is the one number in the whole projection you can control completely.

Common Retirement Planning Mistakes

Most retirement mistakes are about the wrong target, not the wrong calculator.

• Planning on the future-dollar balance. The balance at 65 is $1,400,662.80 in future dollars, but only $577,054.53 in today’s dollars. Compare the today’s-dollars income of $1,923.52 a month with your current spending.
• Ignoring fees. A 1% annual fee cuts the default balance from $1,400,662.80 to $1,159,551.26 — a cost of $241,111.54.
• Starting too late. Starting at 25 instead of 35 adds $805,180.01 to the balance at 65, even on a lower salary.
• Not contributing enough to get the full match. The match is free money. On the default, it is worth $91,278.18 of contributions and $279,313.02 of balance at 65.
• Assuming the 4% rule is a guarantee. It is a rule of thumb built on historical returns. A bad decade early in retirement can break it, and the safe withdrawal rate may be lower.
• Cashing out when changing jobs. Taking $10,000 out before age 59 and a half at a 22% tax rate costs $2,200 of tax plus a $1,000 penalty, leaving $6,800.

Where a Retirement Calculator Decides Things

The balance and the income figure are the numbers behind the biggest retirement decisions.

• Whether you are on track. The targets below show the multiples of salary to aim for at each age.
• When you can retire. The 4% rule income tells you what the balance buys: $4,668.88 a month on the default, or $1,923.52 a month in today’s dollars.
• Whether to raise the contribution. At 5% the balance at 65 is $888,588.93 and the income is $2,961.96 a month; at 15% the balance is $1,866,184.50 and the income is $6,220.61 a month.
• Choosing funds. A 1% fee costs $241,111.54 over 30 years. A low-fee fund keeps that money.
• Planning Social Security. The 4% rule income sits on top of Social Security, so add the two together when you compare with your spending.

Tips for Accurate Results

Five habits keep the retirement projection honest and useful.

1. Use your real match formula. The default is 50% of the first 6%, but your employer’s formula may be different, and it changes the balance a lot.
2. Try a range of returns. Run the calculator at 6%, 7% and 8% and plan on the middle of the range, not the top.
3. Enter your real fee. The default is 0%, but most funds charge something. A 1% fee costs $241,111.54 over 30 years.
4. Check the today’s-dollars figure. The balance at 65 is $1,400,662.80 in future dollars, but only $577,054.53 in today’s dollars at 3% inflation.
5. Compare with the age targets. The table below shows the multiples of salary to aim for at each age, on a $75,000 salary.

Retirement Savings Targets by Age

A common set of targets, on a $75,000 salary, so you can see where the default projection lands.

The default projection is on track against these targets: the calculator’s milestone table shows $205,281.73 at the age-45 milestone and $594,108.85 at the age-55 milestone, against targets of $225,000 at 40 and $450,000 at 50. The balance at 65 is $1,400,662.80, well above the 10-times target of $750,000 at 67. Remember that these targets are rules of thumb, not promises — your spending in retirement is what decides the number you actually need.

401k Retirement Quick Answers

The figures people look up most often about 401(k) retirement income.

Related tools on this site: the main 401(k) calculator, the paycheck calculator for what a higher contribution does to take-home pay, the compound interest calculator for the growth maths, and the salary calculator for converting pay. The IRS publishes the 2026 limits in IR-2025-111.

Frequently Asked Questions

How much monthly income will my 401(k) give me?

Under the 4% rule, divide the balance at 65 by 25 and then by 12. On the default balance of $1,400,662.80, that is $4,668.88 a month, or $1,923.52 a month in today’s dollars.

Is $1 million enough to retire?

It depends on your spending. Under the 4% rule, $1,000,000 gives $3,333.33 a month, or $40,000 a year. On the default projection, $1,400,662.80 gives $4,668.88 a month.

How much should I have saved by 50?

A common target is six times your annual salary by age 50. On a $75,000 salary, that is $450,000. The targets are one times at 30, three times at 40, six times at 50, eight times at 60, and ten times at 67.

What does a 1% fee cost over 30 years?

On the default — age 35, $25,000 balance, $75,000 salary, 10% contribution — a 1% annual fee cuts the balance at 65 from $1,400,662.80 to $1,159,551.26, a cost of $241,111.54.

Is the 4% rule safe?

It is a rule of thumb built on historical returns, not a guarantee. It assumes the money lasts about 30 years. A bad decade early in retirement can break it, so many planners use 3.5% or 4% and adjust spending year by year.

Disclaimer: This calculator gives a projection for general information only and is not financial advice. Investment returns are not guaranteed, tax rules change, and your real balance will differ. Talk to a financial adviser for your situation.