401k Calculator
A 401k calculator projects what your retirement account will be worth when you retire: your own contributions, your employer’s match, and the investment growth on both, year by year. The free 401(k) calculator above does that for any starting age, salary, contribution rate, match formula, return, and fee, and this page explains the result 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 age 65 is $1,400,662.80. Total contributions over 30 years are $395,538.77 — $304,260.59 of your own money and $91,278.18 from your employer — and investment growth adds $980,124.02. The 4% rule turns that balance into $4,668.88 a month of retirement income, or $1,923.52 a month in today’s dollars. The tables below show how each input changes that figure.
How a 401(k) Balance 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. Your contribution is a percentage of your salary, capped at the IRS limit for your age. The employer match follows the formula you pick: a percentage of your pay, up to a percentage of your salary. The final balance is the sum of your contributions, the employer’s contributions, and the investment growth.
On the default example, the first year adds $7,500.00 of your own money and $2,250.00 of employer match, for $9,750.00 of contributions. The balance after year one is $37,182.50. The milestone table shows $205,281.73 at the age-45 milestone and $594,108.85 at the age-55 milestone, and the balance at 65 is $1,400,662.80. Total contributions are $395,538.77, investment growth is $980,124.02, and the 4% rule income is $4,668.88 a month.
Step 1 — Your contribution each year
Your contribution is your rate times your salary, capped at the IRS limit. On the default, 10% of $75,000 is $7,500.00 in year one, and the salary grows 2% a year, so the contribution grows with it.
Step 2 — The employer match
The match is 50% of the first 6% of pay on the default. That is 3% of your salary: $2,250.00 in year one, $91,278.18 over 30 years. A different match formula changes the total a lot.
Step 3 — Growth, fees, and inflation
The balance grows by the return minus the fee each year. The default return is 7% with no fee, and inflation of 3% is used only to show the balance in today’s dollars: $577,054.53, or $1,923.52 a month.
Worked Examples: 401(k) Balance at Different Contribution Rates
Each row is the default example — age 35, $25,000 balance, $75,000 salary, 50% match of the first 6% — run at a different contribution rate, with the balance at 65 and the 4% rule income.
| Contribution rate | Year-1 total | Your total contributions | Balance at 65 | 4% rule income |
|---|---|---|---|---|
| 5% | $5,625.00 | $152,130.30 | $888,588.93 | $2,961.96 / month |
| 10% | $9,750.00 | $304,260.59 | $1,400,662.80 | $4,668.88 / month |
| 15% | $13,500.00 | $456,390.89 | $1,866,184.50 | $6,220.61 / month |
Raising the contribution from 5% to 15% adds $319,473.62 of your own money over 30 years — $456,390.89 minus $152,130.30 — and the balance at 65 rises by $977,595.57, from $888,588.93 to $1,866,184.50. The extra $658,121.95 is investment growth on the extra contributions: growth on the 15% row is $1,293,515.43 against $635,393.48 on the 5% row. At 5%, the employer match is $1,875.00 in year one, because 50% of a 5% contribution is 2.5% of salary; at 10% and 15% the match is maxed out at $2,250.00 in year one, which is 3% of salary.
How to Use the 401k Calculator
Start with the numbers on your pay stub and your plan statement. The more of them you enter, the closer the projection lands.
- Enter your current age. The default is 35. The calculator projects to 65.
- Enter your current 401(k) balance. The default is $25,000.
- Enter your annual salary. The default is $75,000.
- Enter your contribution percentage. The default is 10%. The calculator caps it at the IRS limit and tells you when the cap applies.
- Pick the employer match. The default is 50% of the first 6% of pay. Pick the formula your employer actually offers.
- Enter the expected return, salary growth, fees, and inflation. The defaults are a 7% return, 2% salary growth, no fee, and 3% inflation.
- Read the balance at 65. The big number is the projected balance; the table shows the contributions, the growth, the 4% rule income, and the balance in today’s dollars.
The result updates as you type. Try raising the contribution from 10% to 15% and watch the balance at 65 rise from $1,400,662.80 to $1,866,184.50 — a gain of $465,521.70 for an extra 5% of salary.
Your Default 401(k): $75,000 Salary, 10% Contribution, Age 35
Here is the full maths for the default, so you can check the calculator line by line. You are 35, with a $25,000 balance and a $75,000 salary. You contribute 10%, your employer matches 50% of the first 6%, the return is 7%, salary growth is 2%, there is no fee, and inflation is 3%.
| Item | Amount |
|---|---|
| Balance at age 65 | $1,400,662.80 |
| Your total contributions | $304,260.59 |
| Employer match total | $91,278.18 |
| Total contributions | $395,538.77 |
| Investment growth | $980,124.02 |
| 4% rule income | $4,668.88 / month |
| Balance in today’s dollars | $577,054.53 ($1,923.52 / month) |
| Final salary at 65 | $135,852.12 |
The growth is more than double the contributions: $980,124.02 of growth against $395,538.77 contributed. That is compounding over 30 years. The milestone table shows $37,182.50 after year one, $205,281.73 at the age-45 milestone, and $594,108.85 at the age-55 milestone. Notice how the balance more than doubles between the age-55 milestone and 65 — the last ten years add $806,553.95, because the balance is largest then and the growth is largest too.
Common 401(k) Mistakes to Avoid
Most 401(k) mistakes are about leaving money on the table or expecting too much from the return.
- 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.
- Starting too late. Starting at 25 instead of 35 adds $805,180.01 to the balance at 65, even on a lower salary.
- 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.
- Assuming the return is guaranteed. The 7% return is an assumption, not a promise. At a 6% return the balance is $1,159,551.26; at 8% it is $1,699,668.75.
- 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.
- Forgetting the contribution cap. The 2026 limit is $24,500 under 50. A 15% contribution on a $200,000 salary is capped at $24,500 in year one.
Where You Will Use a 401k Calculator
The projection answers the questions people ask about retirement saving, and the situations below are where it matters most.
- Choosing a contribution rate. At 5% the balance at 65 is $888,588.93; at 15% it is $1,866,184.50. The table shows the trade-off exactly.
- Deciding whether to start now. Starting at 25 gives $2,205,842.81 at 65; starting at 45 gives $998,236.40, even on a higher salary.
- Checking the match. The match formula decides how much free money you get: 100% of the first 6% is $4,500 a year on a $75,000 salary, double the default $2,250.
- Comparing fees. A 1% fee costs $241,111.54 over 30 years on the default. A low-fee fund keeps that money.
- Planning retirement income. The 4% rule turns the balance into monthly income: $4,668.88 a month on the default, or $1,923.52 a month in today’s dollars.
Tips for Accurate Results
Five habits keep the projection honest and useful.
- 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.
- Be honest about the return. Seven percent is a long-run stock market average, not a guarantee. Try 6% and 8% too, and see the range: $1,159,551.26 to $1,699,668.75.
- Enter your real fee. The default is 0%, but most funds charge something. A 1% fee costs $241,111.54 over 30 years.
- Remember the cap. If your contribution rate times your salary is above $24,500, the calculator caps it and tells you.
- 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.
401k Quick Answers
The figures people look up most often about 401(k) plans.
| Question | Answer |
|---|---|
| Balance at 65 on $75,000, 10%, age 35 | $1,400,662.80 |
| Balance at 65 at a 5% contribution | $888,588.93 |
| Balance at 65 at a 15% contribution | $1,866,184.50 |
| 4% rule income on the default | $4,668.88 / month |
| 2026 contribution limit under 50 | $24,500 |
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 will my 401(k) be worth at retirement?
It depends on your age, salary, contribution rate, match, and return. On the default — age 35, $25,000 balance, $75,000 salary, 10% contribution, 50% match of the first 6%, 7% return — the balance at 65 is $1,400,662.80.
What is the 2026 401(k) contribution limit?
The employee limit is $24,500 under age 50, $32,500 at age 50 or older, and $35,750 at ages 60 to 63. The combined employee-plus-employer limit is $72,000.
How much should I contribute to my 401(k)?
At minimum, contribute enough to get the full employer match — that is free money. Beyond that, 10% to 15% of salary is a common target. On a $75,000 salary, 10% gives $1,400,662.80 at 65 and 15% gives $1,866,184.50.
What is the 4% rule?
The 4% rule says you can withdraw 4% of your balance in the first year of retirement and adjust for inflation after that, and the money should last about 30 years. On a $1,400,662.80 balance, that is $56,026.51 a year, or $4,668.88 a month.
Is a 401(k) calculator exact?
No — it is a projection based on the return, salary growth, fees, and inflation you enter. The real return will vary year by year. Use the range: at a 6% return the default balance is $1,159,551.26, and at 8% it is $1,699,668.75.
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.