401(k) Calculator
Project your 401(k) balance at retirement with employer match and salary growth.
Results update as you type.
About this calculator
A 401(k) calculator projects how your workplace retirement account grows to retirement from your salary, the percentage you contribute, your employer’s matching contribution, your expected investment return and annual raises. Contributions compound monthly and the employer match is added on top up to its limit, so you can see how much of the final balance is your money, your employer’s money and investment growth.
Each month it adds your contribution and the matched amount, then applies one-twelfth of the annual return, while your salary and contributions rise with your raises. For example, a 30-year-old earning 60,000, contributing 6% with a 50%-up-to-6% match, 7% returns and 2% raises, reaches roughly 1.01 million by age 65 — of which about 180,000 is your contributions, 90,000 the employer match, and the rest investment growth.
Use it to see whether you are on track, to test how a higher contribution rate or a different return changes the outcome, and above all to confirm you are capturing the full employer match. That match is an immediate, guaranteed return that no other input in the model can rival.
Frequently asked questions
How does the employer match work?
A common formula is 50% of your contributions up to 6% of salary. This tool matches your contribution rate, capped at the match limit, times the match percentage — so contributing 6% with a 50%-up-to-6% match adds 3% of salary in free money each year.
How much should I contribute to my 401(k)?
At a minimum, contribute enough to capture the full employer match — otherwise you leave free money on the table. A common overall target is 10–15% of salary including the match, increased with each raise.
What does "50% match up to 6%" actually mean?
It means your employer adds 50 cents for every dollar you contribute, but only on the first 6% of your salary. So contributing 6% earns the full match — an extra 3% of salary in free money — while contributing less leaves part of that match unclaimed.
What is the 401(k) contribution limit?
The IRS sets an annual cap on employee contributions that rises most years, with an extra catch-up allowance once you are 50 or older; the employer match sits on top of that. This calculator does not enforce the cap, so keep your entered contribution within the current limit.
How does salary growth affect my 401(k)?
Because your contribution is a percentage of salary, every raise automatically increases the dollars you and your employer put in. The annual-raise field compounds this effect, which is why the projected balance is sensitive to even a small assumed pay rise.
What return rate should I assume for a 401(k)?
A diversified stock-and-bond mix has historically returned around 6–8% a year over long periods, so 7% is a common planning assumption. Lower it as you shift toward bonds near retirement, and remember returns are not guaranteed year to year.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/401k/curl
curl "https://calculator.free/api/v1/401k/?current_age=30&retire_age=65&salary=60000&contribution=6"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/401k/?" + new URLSearchParams({
"current_age": "30",
"retire_age": "65",
"salary": "60000",
"contribution": "6"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.