401(k) Calculator — Project Your Retirement Balance

Guide

What Is the 401(k) Calculator?

Last updated: July 2026 · Reviewed by the NeftCal editorial team

A 401(k) calculator projects the balance a US employee's employer-sponsored retirement account will reach by retirement age, combining your own elective deferral, your employer's matching contribution, salary growth, and investment returns compounded monthly. Working as a combined 401k retirement calculator and employer match calculator, it's built for anyone budgeting for retirement, deciding whether to raise their contribution rate, or comparing job offers with different match formulas.

You enter your current age, target retirement age, salary, contribution percentage, employer match terms, any existing 401(k) balance, an expected annual return, and an annual salary growth rate. Each year, the calculator works out your employee contribution — capped at the applicable IRS elective deferral limit for your age that year — then applies the employer match up to the Match Limit % of salary. Contributions are spread evenly across the year and compounded monthly at your expected return, and your salary is increased each year by your entered growth rate to reflect realistic raises over a career.

Who Should Use This Calculator

Employees deciding how much of their paycheck to defer into a workplace plan, job seekers comparing two offers with different match formulas, mid-career savers checking whether they're on track for retirement, and anyone weighing a Traditional vs. Roth 401(k) election alongside other accounts like an IRA or projected Social Security income.

Why It Matters for Financial Planning

A 401(k) is usually the single largest source of retirement savings for US employees, and its final value depends heavily on details that are easy to overlook — whether you're capturing the full employer match, how the IRS elective deferral limit interacts with your contribution rate as your salary grows, and how many decades your money has to compound. Seeing the year-by-year projection makes it clear how much of your eventual balance comes from your own contributions, employer match ("free money" you forfeit if you under-contribute), and pure investment growth — three very different sources that all get blended into a single account balance.

Common Scenarios

Checking whether your contribution rate is high enough to capture the full employer match
Comparing two job offers with different match formulas and starting salaries
Modeling how a raise or promotion changes your projected retirement balance
Deciding between deferring more into a 401(k) versus contributing to a Roth or Traditional IRA
Building a full retirement-income picture alongside projected Social Security benefits

Tips for Accurate Results

At minimum, set your contribution percentage high enough to capture the full employer match — leaving match on the table is leaving free money unclaimed
Update the IRS limit fields whenever the IRS announces new elective deferral limits, since these figures are only the 2025 defaults and change most years
If you've changed jobs and rolled over a prior 401(k) or IRA balance, include it in the Current 401(k) Balance field so the projection starts from your true total
Model a realistic, moderate Annual Salary Growth rate rather than assuming today's raise pace continues indefinitely over a full career
Treat this as a planning estimate, not investment advice — actual market returns vary year to year and rarely compound as smoothly as a fixed average rate

Formula

How Your 401(k) Balance Is Calculated

Growth is simulated monthly on the running balance, with contributions capped by the IRS limit and salary increases applied each year

Annual Contribution & Match

Employee Contribution = min(Salary × Your %, IRS Elective Deferral Limit for Age)
Employer Match = min(Employee Contribution, Salary × Match Limit %) × Match %
Monthly Growth = Opening Balance × (Expected Annual Return ÷ 12 ÷ 100)
Next Year's Salary = Salary × (1 + Annual Salary Growth %)

⚙️ Why This Formula Works

The calculator runs a year-by-year, month-by-month simulation rather than a single closed-form equation, because a 401(k)'s growth depends on several interacting variables: a contribution rate applied to a salary that itself grows every year, a match formula with its own separate cap, and an IRS elective-deferral ceiling that only applies to your own contribution. Each month, contributions (split evenly from the year's total) are added to the balance and investment growth is applied to the running balance — the same additive, compounding mechanic a real plan custodian uses to credit contributions and returns over time.

🎯 When to Use This Formula

Projecting a new or existing 401(k)'s balance at a chosen retirement age
Comparing outcomes at different contribution percentages or employer match formulas
Modeling how a raise, promotion, or new job's salary growth changes your trajectory
Stress-testing a more conservative or more aggressive Expected Annual Return assumption

📋 Assumptions

Your contribution percentage and the employer's match formula stay constant every year
Salary grows at the single, constant Annual Salary Growth rate you enter, not in irregular jumps
You remain continuously employed and fully vested in employer contributions the entire period
The Expected Annual Return you enter is a flat, constant rate applied every month

⚠️ Limitations of the Formula

Doesn't model vesting schedules — an unvested employer match forfeited on an early job change isn't reflected
The IRS elective deferral limit applies to your employee contribution only; it doesn't separately model the higher combined employee-plus-employer limit
Doesn't apply the SECURE 2.0 special catch-up limit for ages 60–63 automatically — adjust the Age 50+ field manually to approximate it
Doesn't model taxes, early withdrawal penalties, loans, or hardship withdrawals — it projects the gross account balance only

Walkthrough

Step-by-Step: How to Use the 401(k) Calculator

From current age to a projected retirement balance in under a minute

Enter your current age and retirement age

Input your current age and the age you plan to retire or stop contributing — the gap between them is how many years the calculator simulates.

Enter your current salary and contribution percentage

Enter your gross annual salary and the percentage of it you elect to contribute (defer) into your 401(k) each year.

Enter your employer match and match limit

Enter the percentage your employer matches per dollar you contribute, and the Match Limit % that caps how much of your salary the employer will match against.

Enter your current balance, expected return, and salary growth

Optionally add any existing 401(k) balance, then set an expected annual investment return and an annual salary growth rate to reflect future raises.

Review the IRS limit fields and click Calculate Balance

Check the editable 2025 IRS elective deferral limit fields for under-50 and age-50-plus, then see your projected balance, total employee contributions, total employer match, and total investment growth, plus a contribution-composition chart and a year-by-year table.

Example

Worked Example

A 35-year projection from age 30 to a 65 retirement, using this calculator's own defaults

Scenario

Suppose a 30-year-old earning $75,000 contributes 10% of salary to a 401(k), with an employer matching 50% up to 6% of salary, a $20,000 starting balance, a 7% expected annual return, and 3% annual salary growth, retiring at 65.

Starting Salary$75,000

Your Contribution10%

Employer Match50% up to 6%

Starting Balance$20,000

Expected Return7% p.a.

Years to Retirement35

Step 1 — Year 1 contribution and match: Employee Contribution = $75,000 × 10% = $7,500 (well under the $23,500 IRS limit). Match base = min($7,500, $75,000 × 6%) = $4,500; Employer Match = $4,500 × 50% = $2,250. Total Year 1 contribution = $9,750.

Step 2 — Salary and contributions grow each year: Salary rises 3% annually (Year 2 salary ≈ $77,250), so both the employee contribution and the employer match grow proportionally every year, never hitting the IRS cap at this contribution rate.

Step 3 — Compound monthly for 35 years: combining the growing contribution stream with the starting $20,000 balance compounding monthly at 7%, the projected balance reaches roughly $2,130,000 (approx.) by age 65.

Step 4 — Break down the sources: of that total, roughly $453,000 comes from your own contributions, roughly $136,000 from employer match, and the remaining approx. $1,520,000 — over 70% of the final balance — comes purely from investment growth compounding over 35 years.

Balance at Retirement

≈ $2,130,000

Employer Match (total)

≈ $136,000

Total Growth

≈ $1,520,000

Contribution Source	Approx. Total	Share of Balance
Starting Balance (compounded)	≈ $213,500	~10%
Your Contributions	≈ $453,000	~21%
Employer Match	≈ $136,000	~6%
Investment Growth	≈ $1,327,000	~63%

Explanation: the figures above are annualized approximations of the calculator's actual month-by-month simulation, shown to illustrate the mechanics — your exact result may differ slightly by a few thousand dollars due to monthly compounding timing. The core takeaway holds either way: over a 35-year career, investment growth dwarfs the dollars actually contributed, which is why starting early and staying invested consistently matters more than trying to time markets or chase a slightly higher return rate.

Match-capture comparison: if this same saver had contributed only 4% instead of 10% (still under the 6% match limit), their own contribution and the match both shrink, but more importantly they'd forfeit a meaningful share of potential compounding — a reminder that under-contributing early costs far more than the missed dollar amount alone once decades of growth are factored in.

Interpretation

Understanding Your 401(k) Projection

A quick way to gauge whether your contribution rate is on track

A widely cited rule of thumb — not an official IRS or regulatory benchmark, just a common planning heuristic — is to save around 15% of gross salary toward retirement each year, counting both your own contribution and any employer match. Comparing your combined contribution rate against that benchmark is a quick way to sanity-check your current savings pace.

Combined Contribution Rate (You + Match)	General Read	Typical Context
Under 10%	Likely under-saving for a full retirement	Early career, tight budget, or not yet capturing full match
10% – 15%	Reasonable, broadly on-track range	Many mid-career savers combining contribution and match
15% and above	Strong savings pace	High earners, late starters catching up, or aggressive early savers

For early-career savers: the biggest lever isn't your contribution percentage today — it's how many years your money has to compound. Even a modest rate started at 25 often outperforms a much higher rate started at 40, purely because of the extra decade and a half of compounding.

For mid-career savers: use the year-wise table to check whether your projected balance is tracking toward a reasonable retirement-income replacement target, and consider whether increasing your contribution percentage after your next raise — rather than letting the extra income simply raise your spending — meaningfully changes the trajectory.

Risk considerations: this calculator assumes a constant expected return and constant salary growth for simplicity. Real markets are volatile year to year, and a sequence of poor early or late returns can meaningfully change your actual outcome versus a smooth average-rate projection like this one.

ℹ️

This tool provides general estimates for educational purposes only and does not constitute personalized financial, tax, or retirement advice. IRS contribution limits, plan rules, vesting schedules, and investment returns can change — consult a licensed financial advisor or your plan administrator before making contribution decisions.

Use Cases

Practical Use Cases for the 401(k) Calculator

Where this 401(k) calculator earns its keep

🎁

Match-capture check

Verify your contribution percentage is high enough to capture 100% of your employer's match before it's left on the table.

📋

Comparing job offers

Model two different salary and match formulas side by side to see the real retirement-savings impact of each offer.

📈

Raise and promotion planning

See how increasing your salary — and optionally your contribution percentage — changes your projected balance.

🎯

Retirement-age planning

Compare projected balances at ages 60, 65, and 70 to weigh the value of working a few extra years.

🔄

Rollover and job-change modeling

Use the Current 401(k) Balance field to project an account that already includes a rolled-over prior employer's plan.

⚖️

Traditional vs. Roth 401(k) planning

Project your balance here, then weigh the tax treatment trade-off using NeftCal's Roth vs Traditional calculator.

🧮

IRS limit sensitivity checks

Update the editable IRS limit fields each year to keep your projection aligned with the latest elective deferral cap.

🧭

Full retirement-income planning

Combine this 401(k) projection with projected Social Security benefits and other savings for a complete retirement picture.

👴

Catch-up contribution modeling

Adjust the Age 50+ IRS limit field to approximate additional catch-up contributions later in your career.

💼

HR and benefits communication

Illustrate the long-term value of a proposed match formula when explaining benefits to employees.

Pros & Cons

Advantages and Limitations

What a 401(k) does well, and where this calculator can't replace a full financial plan

✅ Advantages

Employer match is effectively free money added on top of your own contribution
High annual elective deferral limits compared to an IRA — $23,500 under 50 for 2025, plus catch-up for 50+
Contributions and growth compound tax-deferred (Traditional) or grow tax-free (Roth) until withdrawal
Automatic payroll deduction makes consistent saving effortless once set up
Wide range of investment options curated by the plan, often at low institutional fees
Portable across jobs via direct rollover to a new employer's plan or an IRA
Some plans offer participant loans or hardship withdrawals for genuine financial need
Creditor protection under federal law (ERISA) in most circumstances
Free, instant, and requires no signup or personal information to use this calculator
Runs entirely in your browser — your salary and balance figures are never sent to a server
Editable IRS limit fields keep the projection current as annual limits change
Downloadable plain-text summary of your inputs and results

⚠️ Limitations

Only available through an employer that offers a plan — self-employed individuals need alternatives like a Solo 401(k)
Investment options are limited to the plan's curated menu, unlike a self-directed IRA
Early withdrawals before age 59½ generally trigger income tax plus a 10% penalty
Unvested employer match can be forfeited if you leave before the vesting schedule completes
Traditional 401(k) withdrawals are taxed as ordinary income in retirement
Doesn't model taxes, penalties, loans, hardship withdrawals, or Required Minimum Distributions
Assumes a constant contribution rate, match formula, and return — real plans and markets vary
Not a substitute for a full financial plan built with a licensed advisor

Reference

401(k) vs. Roth IRA vs. Traditional IRA

Quick-reference comparison of three core US retirement accounts

Feature	401(k)	Roth IRA	Traditional IRA
Who offers it	Employer-sponsored plan	Opened independently at a brokerage	Opened independently at a brokerage
Employer match	Common, varies by employer	None	None
2025 contribution limit	$23,500 (+catch-up 50+)	$7,000 (+$1,000 catch-up 50+), income limits apply	$7,000 (+$1,000 catch-up 50+)
Tax treatment	Pre-tax (Traditional) or after-tax (Roth) options	After-tax contributions, tax-free qualified withdrawals	Pre-tax (if deductible), taxed on withdrawal
Investment choices	Limited to plan's menu	Broad — stocks, bonds, funds, and more	Broad — stocks, bonds, funds, and more

Common Mistakes and Expert Tips

❌ Common Mistakes

Contributing less than the employer match threshold and leaving free money unclaimed
Never revisiting the contribution percentage after a raise, so the savings rate quietly stagnates
Using stale IRS elective deferral limits instead of updating the editable fields each year
Assuming employer match is fully yours immediately, ignoring the plan's actual vesting schedule
Cashing out a 401(k) at a job change instead of rolling it over, triggering taxes and a penalty
Modeling an unrealistically high, constant return rate for the entire multi-decade horizon

💡 Expert Tips & Best Practices

Always contribute at least enough to capture the full employer match before considering other accounts
Increase your contribution percentage by 1–2 points with each raise, before the extra income becomes routine spending
Re-run this calculator whenever the IRS announces new elective deferral limits, typically each fall
Compare a Traditional vs. Roth 401(k) election using your current versus expected future tax bracket
Roll over old employer plans promptly rather than leaving multiple scattered small balances

FAQ

Frequently Asked Questions

Common questions about 401(k) plans

What's a good 401(k) contribution percentage?

A common rule of thumb is to contribute at least enough to get your full employer match — it's essentially free money — and then work toward saving around 15% of your salary total (your contribution plus the match) toward retirement over time.

Should I choose a Traditional or Roth 401(k)?

Traditional 401(k) contributions are pre-tax, lowering your taxable income now and taxed on withdrawal, while Roth 401(k) contributions are after-tax with tax-free withdrawals later. Which is better mainly depends on whether you expect your tax rate to be higher now or in retirement — see our Roth vs Traditional IRA Calculator for a fuller side-by-side comparison of the same core tradeoff.

What happens to my 401(k) if I change jobs?

You generally have a few options: leave the balance with your former employer's plan if allowed, roll it over into your new employer's 401(k), or roll it over into an IRA. Rolling over rather than cashing out preserves tax-deferred growth and avoids early withdrawal penalties.

What is 401(k) vesting, and does it affect my employer match?

Vesting is the schedule by which employer contributions become fully yours. Many employers use a graded or cliff vesting schedule over several years — if you leave before you're fully vested, you may forfeit some or all of the unvested employer match. This calculator assumes full vesting; check your plan documents for your actual schedule.

Do 401(k) contribution limits change every year?

Yes. The IRS adjusts elective deferral limits and catch-up limits for inflation most years. This calculator defaults to the 2025 limits — $23,500 under age 50 and $31,000 for age 50 and older — as editable fields. SECURE 2.0 also introduced a higher special catch-up limit of $11,250 for 2025 specifically for ages 60–63, which this simplified calculator doesn't model separately; adjust the 50+ field manually to approximate it.

How does the Employer Match Limit % work?

The Employer Match Limit % caps how much of your salary the employer will match against. For example, a 50% match up to 6% of salary means the employer matches 50 cents per dollar you contribute, but only on the first 6% of your salary that you contribute. Contributing beyond that limit still grows your own balance but stops earning additional match.

Why does my contribution get capped even though I entered a higher percentage?

The calculator caps your annual employee contribution at the applicable IRS elective deferral limit for your age that year — the Under 50 or Age 50+ field — regardless of the contribution percentage you enter. If your salary and percentage would produce a larger amount, only the limit is contributed and compounded that year.

How is investment growth compounded in this calculator?

Contributions are split evenly into monthly amounts and added to your balance each month, with investment growth applied monthly at your Expected Annual Return divided by 12. This monthly compounding produces a smoother, slightly more realistic estimate than compounding the full year's contribution just once a year.

What should I include in the Current 401(k) Balance field?

Enter any existing balance in this or a previous employer's 401(k), including funds already rolled over from an old plan or IRA, so the projection starts from your true total rather than zero.

How does Annual Salary Growth affect my projected balance?

Each year, your salary is increased by the growth rate you enter before that year's contribution and match are calculated, so both your dollar contribution and your employer's match rise along with your raises. This is why even a modest salary growth rate can meaningfully increase the projected balance over a multi-decade career.

What does "Total Growth" mean in the results?

Total Growth is the portion of your projected balance that comes purely from investment returns — your final balance minus your starting balance, minus all employee contributions, minus all employer match. It isolates compounding from the money you and your employer put in directly.

Does this calculator account for taxes or early withdrawal penalties?

No. It projects your gross account balance only and doesn't model income tax on Traditional 401(k) withdrawals, tax-free Roth withdrawals, or early withdrawal penalties. Consult a tax professional for after-tax retirement income planning.

What is the early withdrawal penalty on a 401(k)?

Withdrawals from a Traditional 401(k) before age 59½ are generally subject to ordinary income tax plus a 10% early withdrawal penalty, unless an IRS exception applies (such as certain hardship, disability, or separation-from-service situations). Roth 401(k) contributions can sometimes be withdrawn more favorably, but earnings withdrawn early are generally subject to the same penalty and tax rules. This calculator does not model penalties or taxes — see IRS guidance for the exact rules that apply to you.

What are Required Minimum Distributions (RMDs) from a 401(k)?

Once you reach the IRS-specified RMD age, you're generally required to start withdrawing a minimum amount from a Traditional 401(k) each year, whether or not you need the money, and pay income tax on those withdrawals. Roth 401(k) accounts are no longer subject to RMDs during the original owner's lifetime under current rules. This calculator projects your balance at retirement only — it does not model post-retirement withdrawals or RMDs.

Can I borrow against my 401(k) with a loan or hardship withdrawal?

Many 401(k) plans allow participant loans (often up to 50% of your vested balance or $50,000, whichever is less, repaid with interest through payroll deduction) and hardship withdrawals for specific IRS-defined financial needs. Both reduce your invested balance and its growth potential while the money is out of the market, and an unpaid loan balance can be treated as a taxable distribution if you leave your job. Check your plan document for availability and terms — this calculator doesn't model loans or hardship withdrawals.

How is a 401(k) different from an IRA?

A 401(k) is an employer-sponsored plan you can only access through a workplace, often with an employer match and a plan-specific menu of investment options, and generally higher annual contribution limits. An IRA (Individual Retirement Account) is opened independently at a brokerage, has no employer match, offers a much broader investment selection, but comes with lower annual contribution limits. Many people use both — contributing enough to a 401(k) to capture the full employer match, then contributing to an IRA for additional tax-advantaged savings.