.calc-container {
background: #f8f9fa;
padding: 30px;
border-radius: 12px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
margin-bottom: 40px;
border: 1px solid #e9ecef;
}
.calc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.form-group {
margin-bottom: 20px;
}
.form-label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #495057;
}
.form-input {
width: 100%;
padding: 12px;
border: 2px solid #ced4da;
border-radius: 6px;
font-size: 16px;
transition: border-color 0.15s ease-in-out;
box-sizing: border-box;
}
.form-input:focus {
border-color: #4dabf7;
outline: none;
}
.calc-btn {
display: block;
width: 100%;
padding: 15px;
background-color: #0056b3;
color: white;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 20px;
}
.calc-btn:hover {
background-color: #004494;
}
.results-box {
background: #ffffff;
padding: 25px;
border-radius: 8px;
margin-top: 30px;
border-left: 5px solid #28a745;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
padding-bottom: 12px;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
color: #6c757d;
}
.result-value {
font-weight: bold;
font-size: 18px;
color: #212529;
}
.highlight-value {
color: #28a745;
font-size: 24px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.seo-content h2 {
color: #2c3e50;
margin-top: 35px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
}
.seo-content p {
margin-bottom: 15px;
font-size: 17px;
}
.seo-content ul {
margin-bottom: 20px;
}
.seo-content li {
margin-bottom: 10px;
}
function calculate401k() {
// Get Input Values
var currentAge = parseFloat(document.getElementById('currentAge').value);
var retireAge = parseFloat(document.getElementById('retireAge').value);
var currentBalance = parseFloat(document.getElementById('currentBalance').value) || 0;
var annualSalary = parseFloat(document.getElementById('annualSalary').value) || 0;
var contribPercent = parseFloat(document.getElementById('contribPercent').value) || 0;
var matchPercent = parseFloat(document.getElementById('matchPercent').value) || 0;
var annualReturn = parseFloat(document.getElementById('annualReturn').value) || 0;
// Validate Input
if (isNaN(currentAge) || isNaN(retireAge)) {
alert("Please enter a valid Current Age and Retirement Age.");
return;
}
if (retireAge <= currentAge) {
alert("Retirement age must be greater than current age.");
return;
}
// Calculation Constants
var yearsToGrow = retireAge – currentAge;
var months = yearsToGrow * 12;
var monthlyRate = annualReturn / 100 / 12;
// Logic for contributions
// User contributes X% of salary
var monthlyUserContrib = (annualSalary * (contribPercent / 100)) / 12;
// Employer matches up to Y% of salary, usually based on user contribution
// If user contributes 2% and match is 3%, employer gives 2%.
// If user contributes 6% and match is 3%, employer gives 3%.
var effectiveMatchRate = Math.min(contribPercent, matchPercent);
var monthlyMatchContrib = (annualSalary * (effectiveMatchRate / 100)) / 12;
var totalMonthlyContrib = monthlyUserContrib + monthlyMatchContrib;
var futureBalance = currentBalance;
var totalUserAdded = 0;
var totalMatchAdded = 0;
// Loop through months for compound interest
for (var i = 0; i < months; i++) {
// Add Interest on start-of-month balance
var interest = futureBalance * monthlyRate;
futureBalance += interest;
// Add Contributions
futureBalance += totalMonthlyContrib;
// Track totals
totalUserAdded += monthlyUserContrib;
totalMatchAdded += monthlyMatchContrib;
}
var totalPrincipal = currentBalance + totalUserAdded + totalMatchAdded;
var totalInterest = futureBalance – totalPrincipal;
// Display Results
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
maximumFractionDigits: 0
});
document.getElementById('finalBalance').innerText = formatter.format(futureBalance);
document.getElementById('totalUserContrib').innerText = formatter.format(totalUserAdded);
document.getElementById('totalMatchContrib').innerText = formatter.format(totalMatchAdded);
document.getElementById('totalInterest').innerText = formatter.format(totalInterest);
document.getElementById('resultBox').style.display = 'block';
}
401(k) Retirement Calculator
Estimated Balance at Retirement:
$0.00
Total You Contributed:
$0.00
Total Employer Match:
$0.00
Total Interest Earned:
$0.00
Maximize Your Retirement with a 401(k) Strategy
Planning for retirement is one of the most critical financial steps you can take, and your 401(k) is likely the centerpiece of that strategy. Our 401(k) Retirement Calculator helps you visualize how your current savings, salary contributions, and employer matching can grow over time through the power of compound interest.
How Does This 401(k) Calculator Work?
This tool projects the future value of your retirement account by analyzing several key factors:
- Time Horizon: Calculated by the difference between your current age and planned retirement age. The longer your money stays invested, the more it can grow.
- Contributions: The percentage of your salary you defer into the account. Pre-tax contributions lower your taxable income today while building wealth for tomorrow.
- Employer Match: Often called "free money," this is the amount your employer contributes based on your own savings rate. Always aim to contribute enough to get the full match.
- Compound Growth: The calculation assumes your interest earns interest, accelerating your balance growth exponentially over decades.
Why the Employer Match Matters
In the calculation above, you'll see a specific line for "Total Employer Match." This is crucial because it represents a 100% immediate return on your investment up to the limit. For example, if your employer matches 50% of your contributions up to 6% of your salary, and you earn $60,000, failing to contribute that 6% leaves $1,800 of free money on the table every single year.
Understanding the Formula
While the calculator handles the heavy lifting, the underlying logic uses the standard future value of an annuity formula combined with the future value of a lump sum:
FV = P * (1 + r)^n + PMT * [((1 + r)^n – 1) / r]
Where P is your starting balance, r is the periodic interest rate, n is the number of periods (months), and PMT is your monthly contribution (yours + employer's).
Tips for maximizing your 401(k)
- Start Early: A 25-year-old contributing $200/month will often end up with more than a 35-year-old contributing $400/month due to the extra decade of compounding.
- Increase Contributions Annually: Use the "auto-escalation" feature if your plan offers it, or manually increase your contribution rate by 1% every time you get a raise.
- Watch the Fees: Ensure your investment choices within the 401(k) have low expense ratios to keep more of your returns.