A 35-year-old earning $110,000 wants to know their projected 401(k) balance at 65 with their current 6% contribution and their employer's 3% match. Before the benefits meeting they want to know if they are contributing enough.
401(k) Retirement Calculator
Retirement
A = P × (1 + r/n)^(nt)
Einstein reportedly called compound interest the "eighth wonder of the world." A $10,000 investment at 8% for 30 years grows to over $100,000 — without adding another cent.
Past returns do not guarantee future performance. ASIC MoneySmart
Results are estimates for planning purposes. Verify with current standards and a qualified professional.
1 What this calculator does
Projects 401(k) balance at retirement from current balance, salary, employee contribution percentage and employer match. Applies investment returns monthly and shows projected balance, total contributed, growth component and estimated monthly retirement income using the 4% safe withdrawal rule.
2 Formula & professional reasoning
Annual employee contribution = Salary x Employee%
Annual employer match = Salary x Match%
Total annual contribution = Employee + Employer
FV of current balance = Current balance x (1 + Return)^Years
FV of contributions = Monthly contrib x [(1 + Monthly rate)^Months - 1] / Monthly rate
Total projected = FV current balance + FV contributions
Monthly income estimate (4% rule) = Total balance x 0.04 / 12
The 4% safe withdrawal rule (Bengen 1994) estimates that a retiree can withdraw 4% of their portfolio in the first year and adjust for inflation annually, with a high probability the portfolio lasts 30 years based on historical market returns. The employer match is effectively a 100% instant return on the matched portion -- always contributing at least enough to capture the full match is the single best investment decision available to most employees.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Basic
35-year-old -- current contribution check
Given: Balance: $45,000 | Salary: $110,000 | Employee: 6% | Match: 3% | Age: 35 | Retire: 65 | Return: 7%
Working:
Employee contrib: $6,600/yr | Employer match: $3,300/yr | Total: $9,900/yr ($825/mo) | FV current $45K at 7% over 30 years: $342,867 | FV $825/mo over 360 months at 7%/12: $1,002,818Answer: Projected balance: $1,345,685 | Monthly income (4% rule): $4,486/mo
💡 $4,486/month from the 401(k) alone is a solid foundation. Combined with Social Security (estimated $2,000-3,000/month at 65), total retirement income could be $6,500-$7,500/month.
Standard
Impact of increasing contribution from 6% to 10%
Given: Same as above but employee contribution raised to 10% | Total: 10% + 3% = 13%
Working:
Employee: $11,000/yr | Match: $3,300/yr | Total: $14,300/yr | FV $1,191.67/mo over 30 yrs at 7%: $1,447,839 + FV balance $342,867Answer: Projected balance: $1,790,706 -- $445,000 more than at 6%
💡 Increasing from 6% to 10% adds $4,400/yr in contributions but generates $445,000 more at retirement due to compounding. The cost: $275/month less take-home pay now. At 22% marginal federal rate, the after-tax cost is only $214/month net.
Advanced
Not capturing full employer match -- cost of leaving money on the table
Given: Employee at 2% (not capturing full 3% match) vs 6% (full match captured) | Same everything else
Working:
At 2%: Employee $2,200/yr + Match $2,200/yr = $4,400/yr | At 6%: $6,600+$3,300 = $9,900/yr | Difference: $5,500/yr for 30 years at 7%Answer: Not capturing full match costs approximately $680,000 at retirement
💡 The employer match is a 100% instant return on the matched contributions. Not contributing at least enough to get the full match is the most expensive mistake in retirement planning.
4 Sanity check
2024 IRS contribution limits
Under 50: $23,000 | Age 50+: $30,500 (catch-up) | These are employee-only limits; employer match is additional
4% rule context
Historically safe withdrawal rate for a 30-year retirement | More conservative (3%) recommended for 40+ year retirements | Higher (5%) may work for shorter retirements
Always contribute enough to capture the full employer match
Employer match is a 50-100% instant return -- missing it is the most costly retirement mistake
Traditional vs Roth 401(k)
Traditional: pre-tax contributions, taxable withdrawals | Roth: post-tax contributions, tax-free withdrawals
This calculator models traditional (pre-tax) contributions.
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Not contributing enough to capture the full employer match | Contributing below the match threshold to save take-home pay | Leaving free money unreturned -- equivalent to a permanent pay cut | Always contribute at least enough to get the maximum employer match. If the match is 100% up to 3% of salary, contribute at least 3%. This is the highest guaranteed return available to most investors. |
| Cashing out the 401(k) when changing jobs | Wanting immediate access to the funds at job change | 20% mandatory federal tax withholding + 10% early withdrawal penalty + state taxes = losing approximately 30-40% of the balance | When changing jobs, roll the 401(k) into an IRA or the new employer's plan within 60 days to avoid taxes and penalties. Never cash out unless facing genuine financial emergency. |
| Overestimating 401(k) balance for retirement income | Not accounting for required minimum distributions (RMDs) and taxes on withdrawals | After-tax retirement income lower than projected balance suggests | Traditional 401(k) withdrawals are taxed as ordinary income. A $1.3M balance at 7% withdrawal = $91,000/year in taxable income, potentially pushing into a significant tax bracket. Roth conversions and tax planning before retirement are important. |
| Using a single return rate without testing different scenarios | Planning on the long-run average without considering sequence of returns risk | Retiring into a down market early in retirement can devastate the plan | Run the calculator at 5%, 7% and 9% to understand the range of outcomes. Also consider whether a more conservative allocation near retirement (shifting from growth to balanced) is appropriate. |
6 Reference & regulatory links
7 Professional workflow
Common tools used alongside this one:
Income Tax Calculator
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Compound Interest Calculator
Compound Interest Calculator models the same growth scenario with different assumptions for cross-checking
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Monthly Budget Tracker
Monthly Budget Tracker helps identify cash flow for increased retirement contributions
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