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401(k) Contribution Optimizer

Are you leaving employer match money on the table? Enter your salary, match terms, and tax rate to find your optimal contribution — and see projected balance across current, match-max, 15%, and IRS-max scenarios.

Where this fits

📈 Investing & WealthCash FlowRetirement Plan

This tool lives inside Cash Flow + Retirement Plan and is most useful for people making this kind of decision.

401(k) Limit 2024$23,000
Roth IRA Limit$7,000
S&P 500 Avg Return~10%/yr

You're capturing your full employer match

$5,100/year in employer contributions — consider increasing to 15% or the IRS max to accelerate growth.

Your 401(k) Profile

Account Type

Contributions reduce taxable income now; taxed at withdrawal.

Your Contribution6%
= $5,100/year
0%50%
Marginal Tax Rate (for tax savings)
Projected Balance
$1.3M
At age 65
Monthly Income
$4,375
4% rule at retirement
Tax Savings / Year
$1,122
At 22% marginal rate
Your Monthly Cost
$332
After tax savings

Contribution Scenarios

ScenarioYour AnnualWith MatchProjected Balance
Current (6%)$5,100$10,200$1.3M
Match max (6%)$5,100$10,200$1.3M
15% (recommended)$12,750$17,850$2.3M
IRS max ($23k)$23,000$28,100$3.6M

Assumes 7.0% annual return over 33 years. 4% safe withdrawal rate for monthly income.

Annual Contribution Breakdown

Your contribution (6.0%)$5,100
Employer match+ $5,100
Tax savings (22% bracket)− $1,122
Total going to work for you$10,200/yr
Effective out-of-pocket$332/mo
1

Annual employee contribution

salary × contributionPct ÷ 100

$85,000 × 6% = $5,100

= $5,100

2024 IRS limit: $23,000

2

Employer match contribution

min(contributionPct, matchCeiling) × salary × matchRate ÷ 100

min(6%, 6%) × $85,000 × 100% = $5,100

= $5,100

Employer matches 100% of your contributions up to 6% of salary.

3

Combined monthly contribution

(annualEmployeeContrib + employerContrib) ÷ 12

($5,100 + $5,100) ÷ 12

= $850

4

Projected balance at retirement (future value)

PMT × ((1 + r)ⁿ − 1) ÷ r

$850/mo × ((1 + 0.5833%)^396 − 1) ÷ 0.5833%

= $1.3M

Over 33 years at 7.0% annual return. Monthly income at 4% safe withdrawal rate: $4,375/mo.

Bengen (1994) — 4% safe withdrawal rate

Key insight

Your effective cost after the 22% tax deduction is only $332/month — yet $850/month compounds toward $1.3M at retirement. Employer matching makes the first 6% of contributions the highest-returning investment available to you.

Use this result in →

Roth vs Traditional IRA →Retirement Readiness →Retirement Calculator →

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