401(k) Retirement Calculator
Calculate your 401(k) growth with employer matching, tax advantages, and compound returns. See exactly how much you'll have at retirement and plan your financial future.
Maximizing Your 401(k) for Retirement
Step 1: Get the Full Employer Match
This is the single most important rule of 401(k) investing. Employer matching is literally free money - an instant 25-100% return on your contributions. If your employer offers a match, contribute at least enough to receive it all. For example:
- Company offers: 50% match on contributions up to 6% of salary
- Your salary: $75,000
- You contribute: 6% = $4,500/year
- Company adds: 3% = $2,250/year (free!)
- Total saved: $6,750/year
Step 2: Increase Contributions Over Time
Start where you can and increase gradually. Many plans offer automatic annual increases. A good progression:
- Year 1: 6% (get full match)
- Year 2: 8% (after first raise)
- Year 3: 10% (building momentum)
- Year 5+: 15% (on track for comfortable retirement)
Step 3: Choose Low-Cost Index Funds
Investment selection matters. Here's a simple, proven approach:
- Target-Date Funds: Easiest option - automatically adjusts risk as you age
- S&P 500 Index: Simple, low-cost exposure to US stocks
- Total Market Index: Broader diversification across all US companies
- Three-Fund Portfolio: US stocks (60%), International stocks (30%), Bonds (10%)
401(k) vs IRA: What's the Difference?
| Feature | 401(k) | IRA |
|---|---|---|
| Contribution Limit (2026) | $23,000 ($30,500 age 50+) | $7,000 ($8,000 age 50+) |
| Employer Match | Yes (often 3-6%) | No |
| Investment Options | Limited to plan options | Unlimited |
| Fees | Varies (0.5-2%) | Usually lower (0.03-0.5%) |
| When to Use | First priority (get match!) | After maxing 401(k) match |
Common 401(k) Mistakes to Avoid
- Not contributing enough for full match - Leaving free money on the table
- Cashing out when changing jobs - Lose 30-40% to taxes and penalties
- Being too conservative - Young workers in bonds miss decades of growth
- Ignoring fees - High-fee funds can cost you hundreds of thousands
- Stopping contributions in downturns - Miss buying opportunities
- Not rebalancing - Portfolio drifts away from target allocation
How to calculate 401(k) growth
A 401(k) balance grows from three things at once: the money already in the account compounding, the new contributions you and your employer add each year, and the return those new contributions earn for however long they sit there. One formula covers all three — the future value of a lump sum plus the future value of a stream of contributions.
Future Value = Balance × (1 + r)^n + Annual Contribution × [((1 + r)^n − 1) ÷ r]
Here r is your expected annual return as a decimal (7% becomes 0.07) and n is the number of years until you retire. The annual contribution is not just your own deferral — it includes the employer match, which is why the match does so much of the heavy lifting:
Annual Contribution = (Your Contribution % + Employer Match %) × Salary
Worked example
A $75,000 salary, a 6% contribution, a 50%-up-to-6% match, a $50,000 balance already in the plan, a 7% return, and 25 years to go:
- Your contribution: $75,000 × 6% = $4,500
- Employer match: $75,000 × 6% × 50% = $2,250 — total going in each year is $6,750
- Growth factor: (1 + 0.07)^25 = 5.43
- Existing balance grows to: $50,000 × 5.43 = $271,000
- Contributions grow to: $6,750 × [(5.43 − 1) ÷ 0.07] = $6,750 × 63.2 = $427,000
- Add them together: $271,000 + $427,000 ≈ $698,000
Note that $2,250 of each year's $6,750 — a third of the total — came from the employer. Drop the match and the same 25 years ends near $556,000 instead. The example assumes contributions land at year end; because real contributions arrive every paycheck and start compounding sooner, the calculator above will show a slightly higher figure, and neither version accounts for future raises.
How to maximize your 401(k) match
The match is the highest-return part of the whole account, and it is calculated with a formula you can plan around:
Employer Match = Salary × min(Your Contribution %, Match Cap %) × Match Rate
The min() is the important part: contributing above the cap earns you nothing extra in match. On that $75,000 salary with a 50%-up-to-6% formula, contributing 4% collects $75,000 × 4% × 50% = $1,500 instead of the full $2,250 — $750 given up every year. Contributing 10% still collects $2,250, because the cap binds at 6%. Four practical rules follow from that:
- Hit the cap first. Before an IRA, before extra mortgage payments, fund your 401(k) up to the match cap. A 50% match is an instant 50% return.
- Spread contributions across all pay periods. Most plans match per paycheck. Hitting the IRS annual limit in September stops your deferrals for the rest of the year and, unless the plan offers a year-end "true-up," forfeits the match on those final paychecks.
- Read your plan's exact formula. A tiered safe-harbor formula (dollar-for-dollar on the first 3%, then 50% on the next 2%) needs a 5% contribution to be fully collected, not 6% — the cap differs from plan to plan.
- Check the vesting schedule. Matched dollars often vest over three to five years. Leaving a month before a vesting cliff can hand back thousands you already counted as yours; your own contributions are always 100% yours.
What these numbers mean
Treat the projection as a range, not a promise. Returns arrive unevenly, so a 7% average can still mean a decade that goes nowhere followed by a decade that does the work. A useful sanity check is the 4% rule: divide the projected balance by 25 to see the rough annual income it supports — that $698,000 becomes about $27,900 a year before tax, on top of Social Security. If that falls short of what you need, the two levers with the biggest effect are your contribution rate and the number of years you leave it invested, not the return assumption you type in.
Frequently Asked Questions
How much should I contribute to my 401(k)?▼
At minimum, contribute enough to get the full employer match - it's free money! Ideally, aim for 10-15% of your salary. The 2026 IRS limit is $23,000 per year ($30,500 if age 50+).
What is employer matching?▼
Employer matching is when your company contributes money to your 401(k) based on your contributions. For example, "50% match up to 6%" means if you contribute 6% of salary, they add 3%. This is an instant 50% return on your money!
What return should I expect from my 401(k)?▼
Historical stock market returns average 7-10% annually. Conservative estimates use 6-7%, moderate 7-8%, and aggressive 8-10%. Your actual returns depend on your investment choices and market conditions.
Can I access my 401(k) money before retirement?▼
Yes, but with penalties. Withdrawals before age 59½ typically incur a 10% penalty plus income tax. Exceptions exist for hardship withdrawals, loans (if plan allows), and Rule of 55 for those leaving jobs at 55+.
What is the 4% withdrawal rule?▼
The 4% rule suggests withdrawing 4% of your retirement savings annually for sustainable income. For a $1 million 401(k), that's $40,000/year. Research shows this provides a 95% probability your money will last 30+ years in retirement.
Should I do Roth 401(k) or Traditional 401(k)?▼
Traditional 401(k) contributions are pre-tax (tax deduction now, pay taxes in retirement). Roth 401(k) contributions are after-tax (no deduction now, tax-free withdrawals). Choose Traditional if you expect lower taxes in retirement, Roth if higher. Many do both.
What happens to my 401(k) if I change jobs?▼
You have options: (1) Leave it with old employer, (2) Roll over to new employer's plan, (3) Roll over to an IRA, (4) Cash out (not recommended due to taxes and penalties). Rolling over to an IRA often provides the most investment options.
How do 401(k) fees affect my returns?▼
Fees matter enormously! A 1% fee difference can cost hundreds of thousands over a career. Look for low-cost index funds with expense ratios under 0.20%. Avoid funds with loads or 12b-1 fees.
How do you maximize your 401(k) match?▼
Contribute at least the percentage your plan matches up to, and spread those contributions across every paycheck of the year. The match is calculated as salary × the lower of your contribution rate or the match cap × the match rate — so on a "50% up to 6%" formula at a $75,000 salary, contributing 6% earns $2,250 while contributing 4% earns only $1,500. Because most plans match per paycheck, maxing out early in the year can stop your contributions and forfeit the match on later paychecks unless your plan offers a true-up. Also check the vesting schedule: matched dollars you leave before vesting go back to the employer.
How do you calculate 401(k) growth?▼
Compound your current balance forward and add the future value of your yearly contributions: FV = Balance × (1 + r)^n + Annual Contribution × [((1 + r)^n − 1) ÷ r], where r is your annual return as a decimal and n is years to retirement. Your annual contribution is your own deferral plus the employer match. Because you are compounding both the existing balance and every new contribution, the growth curve steepens sharply in the final decade — which is why raising your contribution rate early matters more than picking the perfect fund.