How a 401(k) grows
A 401(k) is a workplace retirement account: money goes in straight from your paycheck (often before tax), your employer frequently matches part of it, and the whole balance compounds for decades. This calculator projects that growth month by month up to your retirement age, then shows how long it would last once you start drawing on it.
The single biggest lever most people overlook is the employer match. Capturing a full 4% match on a typical salary can add hundreds of thousands of dollars over a career — money you’d miss out on by contributing too little. We add it to your projection automatically so you can see its real impact.
Are you on track?
The verdict at the top reads your plan as On track, Almost there, or Let’s close the gap — never a pass/fail. The numbers stay honest, but any shortfall comes with the exact fix: how much more per month, or how many extra years, would close it. Every assumption — returns, inflation, how long you plan for — is visible and editable, so the result is never a black box.
Frequently asked questions
How much will my 401(k) be worth at retirement?
It depends on what you contribute, your employer match, your returns, and how many years you have left. As a rough guide, contributing $600 a month for 30 years at a 7% return grows to well over $700,000 — and the employer match can add a six-figure chunk on top for free. Enter your salary, contribution, and match above to see your projected balance and whether it’s on track.
How does a 401(k) employer match work?
Many employers match part of what you put in — for example, 100% of your contributions up to 4% of your salary. On a $70,000 salary, a 4% match is about $2,800 a year, or roughly $233 a month, added to your account at no cost to you. It’s one of the highest-return moves in personal finance, which is why this calculator folds it straight into your projection.
What is a good 401(k) contribution percentage?
A common target is 15% of your salary, including the employer match. If your employer matches up to a certain percent, contributing at least enough to capture the full match is the first priority — anything less leaves free money on the table. Use the sliders to see how raising your contribution changes the projected balance.
Can I retire on my 401(k) alone?
Often a 401(k) is the largest piece, but not the whole picture. Social Security typically covers part of your spending, and you may have other savings. This calculator combines your 401(k) projection with Social Security and a safe withdrawal rate to show whether the total is enough — and exactly what to change if it isn’t.
Worked examples
Each scenario below is computed by the same retirement engine that powers the interactive calculator above — no hand-typed numbers.
Standard 401k contributor
$30,000 in a 401k at age 32, contributing $800/month with a 50% match up to 6% of a $60,000 salary — modeling growth to retirement at 65.
Projected nest egg
$1,767,072
Required (today's $)
$769,510
Funded ratio
87%
Monthly income
$4,021/mo
The employer match adds $150/month effectively, bringing total monthly contributions to $950. Over 33 years this additional $150/month compounds to a significant additional balance.
Maxing the 401k at 45
$180,000 saved at 45, maxing annual 401k contributions ($23,000 in 2024 = ~$1,917/month), retiring at 65 with $80,000/year spending target.
Projected nest egg
$1,725,589
Required (today's $)
$1,001,967
Funded ratio
95%
Monthly income
$5,685/mo
Maxing the 401k for 20 years produces a substantial nest egg even starting at 45 — and after 50, the catch-up limit allows an extra $7,500/year.
Projected 401k balance by contribution level and retirement age
$50,000 starting balance at age 35, 7% annual return, 3% inflation.
| Monthly 401k contribution ($) | 60 | 62 | 65 | 67 |
|---|---|---|---|---|
| $500 | $691K | $808K | $1M | $1M |
| $800 | $934K | $1M | $1M | $2M |
| $1,200 | $1M | $1M | $2M | $2M |
| $1,917 | $2M | $2M | $3M | $3M |
$1,917/month = 2024 IRS 401k maximum ($23,000/year). After age 50, the limit rises to $30,500/year ($2,542/month).
What affects your retirement outcome
Contribution amount
More contributed = more compounding. The IRS limits annual 401k contributions to $23,000 in 2024 ($30,500 after 50).
Employer match
A 50% match up to 6% of salary is equivalent to a 50% instant return on those dollars — always contribute enough to capture the full match.
Investment selection within 401k
Low-cost index funds (expense ratio <0.2%) vs high-fee actively managed funds can differ by 0.5–1% per year — which compounds to a significant difference over 30 years.
Practical takeaways
- ✓Always contribute at least enough to get the full employer match before any other savings decision.
- ✓After the match, consider maxing an IRA (Roth or traditional) before contributing beyond the match in the 401k — IRAs often have lower fees and more investment options.
- ✓Set contributions to auto-escalate 1% per year when you get a raise — this maintains your lifestyle while growing your savings rate automatically.
More retirement questions
What is the 401k contribution limit for 2024?
The employee contribution limit is $23,000 in 2024. If you are 50 or older, you can contribute an additional $7,500 in catch-up contributions, for a total of $30,500. These limits apply to traditional and Roth 401k contributions combined. Employer contributions and profit-sharing can bring the total to $69,000 (or $76,500 with catch-up).
Should I choose traditional or Roth 401k contributions?
Traditional contributions reduce your taxable income now and are taxed at withdrawal. Roth contributions are made after-tax and grow and withdraw tax-free. If you expect to be in a higher tax bracket in retirement, Roth is likely better. If you expect a lower bracket in retirement, traditional is usually better. Many employers now offer both — splitting between them provides tax diversification.
What this calculator does — and does not — compute
Retirement projections involve inputs that come from government agencies, employers, and tax rules this tool cannot access. Here is exactly what you are providing versus what this calculator handles on its own.
- 1.Social Security is not calculated here. You enter your own monthly estimate in the “Other monthly income” field. This tool does not access your earnings record or apply Social Security benefit formulas. To get your actual personalized estimate, create a free account at ssa.gov/myaccount.
- 2.Required Minimum Distributions (RMDs) are not modeled. The drawdown projection shows balance depletion under your stated withdrawal rate, but it does not enforce IRS RMD schedules (which begin at age 73 for most accounts) or calculate RMD amounts from IRS life-expectancy tables. If RMDs apply to you, actual withdrawals may differ from the projection shown.
- 3.Pension income is an input you provide, not a computed output. If you have a defined-benefit pension, enter your expected monthly payment in “Other monthly income.” This tool does not compute pension formulas (FERS, CalPERS, military, state, or private plan formulas) and does not connect to any employer or government pension system.
- 4.Withdrawal tax treatment is simplified and illustrative. The projection shows gross withdrawals from your portfolio. It does not calculate federal or state income taxes on traditional 401k or IRA distributions, does not model Roth tax treatment, and does not account for RMD-driven bracket changes. Actual after-tax income will differ. For tax planning specific to your situation, consult a qualified tax professional.
- 5.Any depletion result is a projection, not a guarantee. “How long your money lasts” and similar outputs are calculated under your stated return rate, inflation rate, and spending assumptions. Actual outcomes depend on market performance, sequence of returns, unexpected expenses, and life events that cannot be modeled in advance. A projection is a planning tool, not a promise.
This calculator is for educational and planning purposes only. It does not constitute financial, tax, or investment advice.