Project your 401(k) balance, optimize your employer match, check IRS contribution limits, and compare traditional vs. Roth splits. Free, ad-free, and entirely private — all calculations run in your browser.
401(k) Planner
Project your 401(k) balance, optimize your employer match, check contribution limits, and compare traditional vs. Roth splits.
Your Profile
Employer Match Formula
100% up to 3%, 50% up to 5%
Traditional vs. Roth Split
All contributions are traditional (pre-tax). See the Roth Conversion Calculator for a deeper tax analysis.
Auto-updates as you adjust inputs · 2026 limits
Educational purposes only. This tool is for educational purposes only and is not financial advice. It provides projections based on the assumptions you enter and publicly available IRS contribution limits. Employer match formulas, vesting schedules, and plan features vary by employer. Consult a licensed financial advisor for guidance specific to your situation.
Methodology
How the match optimization, contribution-limit checks, and growth projection work in plain language.
1 Employer Match Optimization
Many employers offer a matching contribution on your 401(k) deferrals — essentially free money toward your retirement. The tool supports common two-tier match formulas such as "100% up to 3%, 50% up to 5%".
If your contribution rate is below the total of the match tiers (e.g., you contribute 2% but your employer matches up to 5%), the tool flags this prominently. It calculates:
- Your current match dollars — what your employer puts in at your current contribution rate
- Your max possible match — what you'd get if you contributed enough to capture the full match
- Missed match dollars — the annual amount left on the table
2 IRS Contribution Limit Check
The IRS sets an annual cap on how much you can defer into a 401(k) plan. For 2026, the elective deferral limit is $24,500, with an additional $8,000 catch-up allowed if you're age 50 or older (or $11,250 for ages 60–63 under SECURE 2.0).
If your planned annual contribution would exceed the applicable limit, the tool warns you. The limit is calculated as the base deferral limit plus any catch-up amount you're eligible for based on your current age.
3 Growth Projection
The tool projects your balance from your current age to retirement using:
- Employee contributions — your contribution rate applied to your salary, reinvested each year
- Employer match — calculated from your match formula each year
- Investment growth — annual compounding on the total balance using your expected return rate
- Salary growth — your salary increases annually at your specified rate, growing both your contributions and match
The stacked chart visualizes these three layers (employee contributions, employer match, investment growth) as separate colored areas that build up over time to show the total balance. Growth is modeled with annual compounding and a mid-year approximation for new contributions.
4 Traditional vs. Roth 401(k)
The tool allows you to split your contributions between traditional (pre-tax) and Roth (after-tax) 401(k) accounts. The split affects only your tax treatment:
- Traditional 401(k): Contributions reduce your current taxable income, but withdrawals in retirement are taxed as ordinary income.
- Roth 401(k): Contributions are made with after-tax dollars, but qualified withdrawals in retirement are tax-free.
This tool provides a summary of the tax implications of your chosen split. For a deeper traditional vs. Roth analysis — including conversion strategies, break-even rates, and multi-year ladders — use the Roth Conversion Calculator.
Model defaults: 6% annual return · 3% salary growth · Annual compounding · Mid-year contribution growth approximation · No fees or expense ratios modeled.
Last updated: August 2, 2026 · Contribution limits reviewed annually. Growth assumptions reviewed quarterly.
Annual review comment: Next scheduled limit review — Q4 2026, when IRS publishes 2027 cost-of-living adjustments for elective deferral and catch-up limits.
Frequently Asked Questions
Answers to common questions about 401(k) plans, employer matching, contribution limits, and how this calculator works.
What is a 401(k)?
A 401(k) is an employer-sponsored retirement savings account that lets you contribute a portion of your paycheck on a pre-tax (Traditional) or after-tax (Roth) basis. Contributions grow tax-deferred or tax-free depending on the account type, and many employers add a matching contribution — essentially free money. The plan is named after Section 401(k) of the Internal Revenue Code and is the most common defined-contribution retirement plan in the U.S., covering roughly 65 million active participants according to the U.S. Department of Labor.
How does employer matching work?
An employer match is a contribution your employer adds to your 401(k) based on how much you contribute yourself. A common formula is "100% match on the first 3% of salary, plus 50% on the next 2%." For example, if you earn $80,000 and contribute 5% ($4,000), your employer adds $2,400. Not contributing enough to capture the full match is the most common 401(k) mistake — it means leaving an immediate 50–100% return on the table. Fidelity reports that roughly 88% of employers offering a 401(k) provide some form of matching.
What are the current 401(k) contribution limits?
For 2025, the employee elective deferral limit is $23,500. If you are age 50 or older, you can contribute an additional $7,500 in catch-up contributions, bringing your total to $31,000. Starting in 2025, the SECURE 2.0 Act allows participants ages 60–63 to make super catch-up contributions of $11,250 instead of the standard $7,500. Employer matching contributions do not count toward the employee deferral limit — they count toward the separate total annual additions limit of $70,000 (or $77,500 with catch-up). These limits are set by the IRS and reviewed annually.
How much should I contribute to my 401(k)?
A widely recommended target is to contribute at least enough to capture your full employer match — this is the minimum, as it represents an immediate return on your money. Beyond that, many financial advisors suggest saving 10–15% of your gross income for retirement, including any employer match. If you are behind on savings, consider maxing out your contributions ($23,500 for 2025, or $31,000 if 50+). Start where you can and increase by 1% each year. This calculator lets you model different contribution rates to see how they affect your projected retirement balance.
Should I contribute enough to get the full employer match?
Yes — contributing at least enough to get the full employer match is widely considered the single most important 401(k) decision you can make. If your employer matches 100% of the first 3% of salary, not contributing 3% means forfeiting free money every pay period. Over a 30-year career, the lost match and its compounding growth can amount to hundreds of thousands of dollars. Schwab, Fidelity, and the U.S. Department of Labor all identify capturing the full match as the first priority before directing savings to other accounts like a Roth IRA or taxable brokerage.
What happens if I exceed the annual contribution limit?
Excess deferrals — contributions beyond the IRS annual limit — must be returned to you by April 15 of the following year. If not corrected, the excess is taxed twice: once in the year contributed and again when withdrawn. Your employer's plan administrator is required to monitor contributions and prevent excess deferrals across multiple employers, but if you hold more than one job with 401(k) plans, it is your responsibility to ensure combined deferrals stay within the limit. The IRS may impose penalties if excess contributions are not timely corrected.
Should I choose a Traditional or Roth 401(k)?
The choice depends on whether you expect your tax rate to be higher now or in retirement. A Traditional 401(k) reduces your taxable income today but is taxed on withdrawal in retirement. A Roth 401(k) uses after-tax dollars but provides tax-free withdrawals in retirement. If you expect to be in a higher tax bracket in retirement, the Roth 401(k) is generally more advantageous. If you expect a lower bracket, Traditional may save more. Some workers split contributions between both for tax diversification. Fidelity recommends considering your current vs. expected future tax rate, state tax laws, and existing retirement accounts when deciding.
How much could my 401(k) grow by retirement?
That depends on your contribution rate, employer match, investment returns, and time horizon. As a simple example, contributing $500/month starting at age 30 with a 7% average annual return grows to over $1.2 million by age 65 — and that does not include employer matching. This calculator projects your balance year by year, showing the breakdown between your contributions, employer match, and investment growth. You can adjust the expected annual return (4–10%), salary growth rate, and retirement age to model conservative, moderate, and aggressive scenarios.
Is my data stored or shared?
No. All calculations in this 401(k) planner run entirely in your browser using JavaScript. No data is sent to any server, no cookies are set for tracking, and no account or login is required. Your financial information never leaves your device. This tool is completely private and ad-free by design.
Is this calculator financial advice?
No. This 401(k) calculator is an educational tool designed to help you model retirement savings scenarios and understand how different variables affect your projected balance. It is not a substitute for professional financial advice. Employer match formulas, vesting schedules, plan features, and tax implications vary by employer and individual circumstances. Consult a licensed financial advisor or tax professional for guidance specific to your situation.
What Is a 401(k)?
A 401(k) plan is an employer-sponsored retirement savings account that lets you contribute a portion of your paycheck before or after taxes through a Traditional or Roth 401(k). Named after Section 401(k) of the Internal Revenue Code, it is the most common defined-contribution retirement plan in the U.S. According to the U.S. Department of Labor, 401(k) plans cover roughly 65 million active participants.
For 2025, the IRS set the employee elective deferral limit at $23,500, with an additional $7,500 catch-up for those 50+. Total contributions including employer match are capped at $70,000 (or $77,500 with catch-up).
How Employer Matching Works
An employer match is a contribution your employer adds to your 401(k) based on your own deferrals — essentially free money for retirement. A common formula is "100% on the first 3% of salary, 50% on the next 2%." If you earn $80,000 and contribute 5% ($4,000), your employer adds $2,400.
Fidelity reports roughly 88% of employers offering a 401(k) provide a match. Not contributing enough to capture the full match is an immediate 50–100% return you cannot replicate elsewhere. This calculator highlights whether your current contribution level captures your full match.
401(k) Contribution Limits Explained
The IRS sets annual limits on 401(k) deferrals. For 2025, the employee contribution limit is $23,500, with an additional $7,500 catch-up for those 50+. Under the SECURE 2.0 Act, participants ages 60–63 can make super catch-up contributions of $11,250.
Employer matching contributions do not count toward the employee deferral limit — they count toward the total annual additions limit ($70,000 for 2025, or $77,500 with catch-up). This means your employer's match is bonus savings on top of your own contributions.
Salary Growth & Investment Returns
Projecting your 401(k) balance at retirement requires accounting for two key variables: salary growth and investment returns. Most financial planners assume a 2–3% annual salary increase to account for raises and promotions. This calculator defaults to 3% salary growth, which you can adjust to match your personal expectations.
On the investment side, historical stock market returns have averaged roughly 7–10% annually over long periods, though past performance does not guarantee future results. Vanguard recommends using a diversified portfolio aligned with your risk tolerance and time horizon. This tool lets you model different return scenarios — from conservative (4%) to aggressive (10%) — so you can stress-test your retirement projection.
The power of compound interest is the single biggest driver of long-term wealth building. A $500 monthly contribution earning 7% annually grows to over $1.2 million in 30 years. Even small increases in your contribution rate — just 1–2% per year — can add hundreds of thousands of dollars to your ending balance over a full career. Use our Compound Interest Calculator to explore this effect in detail.
Common 401(k) Mistakes to Avoid
Even with a well-intentioned savings plan, many workers make avoidable mistakes that significantly reduce their retirement balance:
- Not capturing the full employer match. This is the costliest error — it's leaving free money on the table every pay period. This single mistake can cost tens of thousands of dollars over a career.
- Cashing out when changing jobs. Withdrawing your 401(k) when leaving an employer triggers income taxes plus a 10% penalty if under 59½. Roll the balance into your new employer's plan or an IRA instead.
- Ignoring fees. High expense ratios erode returns significantly. A 1% annual fee on a $500,000 balance can cost over $100,000 in lost growth over 20 years.
- Overconcentrating in company stock. A balanced mix of stocks, bonds, and international funds reduces risk.
- Not increasing contributions over time. If your salary grows but your contribution rate stays flat, you are saving less relative to your income. Automate annual 1% increases.
Traditional vs. Roth 401(k): Which Should You Choose?
The choice between a Traditional and Roth 401(k) comes down to when you want to pay taxes. With a Traditional 401(k), contributions are made pre-tax, reducing your current taxable income. You pay taxes on withdrawals in retirement. With a Roth 401(k), contributions are made after taxes, but qualified withdrawals in retirement are completely tax-free.
If you expect to be in a higher tax bracket in retirement than you are now, the Roth 401(k) is generally advantageous. If you expect a lower bracket in retirement, Traditional may save more. Many financial advisors — including guidance from Fidelity — recommend considering your current vs. expected future tax rate, state tax laws, and whether you already have other tax-advantaged accounts.
Some workers split contributions between both types for tax diversification. Use the Roth vs. Traditional comparison built into this calculator to model your specific scenario. You can also explore our dedicated Roth IRA Calculator and Roth Conversion Calculator for additional retirement tax planning strategies.
How to Use This 401(k) Calculator
Our 401(k) retirement calculator is designed to be simple yet powerful. Enter your current age, salary, current 401(k) balance, and contribution percentage. The tool will automatically calculate your employer match, project your balance to retirement age, and show you a growth chart broken down by your contributions, employer match, and investment growth.
You can adjust your expected annual return, salary growth rate, and retirement age to model different scenarios. The calculator also lets you compare Traditional vs. Roth contributions side by side, so you can see which option maximizes your after-tax retirement balance.
For a more comprehensive retirement plan, pair your 401(k) projection with our FIRE Planner, which uses Monte Carlo simulation to test your plan across hundreds of market scenarios in five different retirement modes — Regular, Coast, Lean, Fat, and Barista FIRE. You can also track your overall financial picture with the Net Worth Tracker and optimize health savings with the HSA Calculator.
All calculations run entirely in your browser — no data is sent to any server, no account is required, and there are no ads. Your financial information stays completely private.
Sources & Last Updated
The figures below should be reviewed quarterly. Each is linked to its primary source.