Colorado Payroll Calculator
Payroll Summary per Pay Period
Gross Pay: $0.00
Pre-Tax Deductions: $0.00
Taxable Gross Pay (Federal/State/FICA): $0.00
Federal Income Tax Withholding: $0.00
Social Security Tax: $0.00
Medicare Tax: $0.00
Colorado State Income Tax: $0.00
Colorado FAMLI Employee Contribution: $0.00
Post-Tax Deductions: $0.00
Net Pay: $0.00
function calculatePayroll() {
// Input values
var grossPay = parseFloat(document.getElementById('grossPay').value);
var payFrequency = parseFloat(document.getElementById('payFrequency').value); // Number of pay periods per year
var federalFilingStatus = document.getElementById('federalFilingStatus').value;
var preTaxDeductions = parseFloat(document.getElementById('preTaxDeductions').value);
var postTaxDeductions = parseFloat(document.getElementById('postTaxDeductions').value);
var additionalFederalWithholding = parseFloat(document.getElementById('additionalFederalWithholding').value);
// Validate inputs
if (isNaN(grossPay) || grossPay < 0) {
alert('Please enter a valid Gross Pay.');
return;
}
if (isNaN(preTaxDeductions) || preTaxDeductions < 0) {
alert('Please enter valid Pre-Tax Deductions.');
return;
}
if (isNaN(postTaxDeductions) || postTaxDeductions < 0) {
alert('Please enter valid Post-Tax Deductions.');
return;
}
if (isNaN(additionalFederalWithholding) || additionalFederalWithholding < 0) {
alert('Please enter valid Additional Federal Withholding.');
return;
}
// Constants (2024 rates)
var SOCIAL_SECURITY_RATE = 0.062;
var MEDICARE_RATE = 0.0145;
var SOCIAL_SECURITY_WAGE_BASE = 168600; // For Social Security and FAMLI
var COLORADO_STATE_TAX_RATE = 0.044;
var COLORADO_FAMLI_EMPLOYEE_RATE = 0.0045;
// Calculate annualized values
var annualGrossPay = grossPay * payFrequency;
var annualPreTaxDeductions = preTaxDeductions * payFrequency;
// 1. Calculate Taxable Gross Pay for FICA, State, and Federal
var taxableGrossPayFICAStateFederal = grossPay – preTaxDeductions;
if (taxableGrossPayFICAStateFederal < 0) taxableGrossPayFICAStateFederal = 0;
// 2. Calculate FICA Taxes (Social Security & Medicare)
var socialSecurityTax = 0;
var medicareTax = 0;
var annualTaxableGrossForFICA = annualGrossPay – annualPreTaxDeductions;
if (annualTaxableGrossForFICA < 0) annualTaxableGrossForFICA = 0;
// Social Security
var annualSocialSecurityTaxable = Math.min(annualTaxableGrossForFICA, SOCIAL_SECURITY_WAGE_BASE);
socialSecurityTax = (annualSocialSecurityTaxable * SOCIAL_SECURITY_RATE) / payFrequency;
// Medicare
medicareTax = (taxableGrossPayFICAStateFederal * MEDICARE_RATE);
// 3. Calculate Colorado FAMLI Employee Contribution
var coloradoFamli = 0;
var annualFamliTaxable = Math.min(annualTaxableGrossForFICA, SOCIAL_SECURITY_WAGE_BASE); // FAMLI also capped at SS wage base
coloradoFamli = (annualFamliTaxable * COLORADO_FAMLI_EMPLOYEE_RATE) / payFrequency;
// 4. Calculate Colorado State Income Tax
var coloradoStateTax = taxableGrossPayFICAStateFederal * COLORADO_STATE_TAX_RATE;
// 5. Calculate Federal Income Tax Withholding (Simplified Approximation)
var federalTax = 0;
var annualFederalTaxableIncome = annualGrossPay – annualPreTaxDeductions;
if (annualFederalTaxableIncome < 0) annualFederalTaxableIncome = 0;
var standardDeduction = (federalFilingStatus === 'single') ? 14600 : 29200; // 2024 Standard Deductions
annualFederalTaxableIncome -= standardDeduction;
if (annualFederalTaxableIncome < 0) annualFederalTaxableIncome = 0;
// Federal Tax Brackets (2024) – Simplified for withholding approximation
if (federalFilingStatus === 'single') {
if (annualFederalTaxableIncome <= 11600) {
federalTax = annualFederalTaxableIncome * 0.10;
} else if (annualFederalTaxableIncome <= 47150) {
federalTax = (11600 * 0.10) + ((annualFederalTaxableIncome – 11600) * 0.12);
} else if (annualFederalTaxableIncome <= 100525) {
federalTax = (11600 * 0.10) + (35550 * 0.12) + ((annualFederalTaxableIncome – 47150) * 0.22);
} else if (annualFederalTaxableIncome <= 191950) {
federalTax = (11600 * 0.10) + (35550 * 0.12) + (53375 * 0.22) + ((annualFederalTaxableIncome – 100525) * 0.24);
} else if (annualFederalTaxableIncome <= 243725) {
federalTax = (11600 * 0.10) + (35550 * 0.12) + (53375 * 0.22) + (91425 * 0.24) + ((annualFederalTaxableIncome – 191950) * 0.32);
} else if (annualFederalTaxableIncome <= 609350) {
federalTax = (11600 * 0.10) + (35550 * 0.12) + (53375 * 0.22) + (91425 * 0.24) + (51775 * 0.32) + ((annualFederalTaxableIncome – 243725) * 0.35);
} else {
federalTax = (11600 * 0.10) + (35550 * 0.12) + (53375 * 0.22) + (91425 * 0.24) + (51775 * 0.32) + (365625 * 0.35) + ((annualFederalTaxableIncome – 609350) * 0.37);
}
} else { // Married Filing Jointly
if (annualFederalTaxableIncome <= 23200) {
federalTax = annualFederalTaxableIncome * 0.10;
} else if (annualFederalTaxableIncome <= 94300) {
federalTax = (23200 * 0.10) + ((annualFederalTaxableIncome – 23200) * 0.12);
} else if (annualFederalTaxableIncome <= 201050) {
federalTax = (23200 * 0.10) + (71100 * 0.12) + ((annualFederalTaxableIncome – 94300) * 0.22);
} else if (annualFederalTaxableIncome <= 383900) {
federalTax = (23200 * 0.10) + (71100 * 0.12) + (106750 * 0.22) + ((annualFederalTaxableIncome – 201050) * 0.24);
} else if (annualFederalTaxableIncome <= 487450) {
federalTax = (23200 * 0.10) + (71100 * 0.12) + (106750 * 0.22) + (182850 * 0.24) + ((annualFederalTaxableIncome – 383900) * 0.32);
} else if (annualFederalTaxableIncome <= 731200) {
federalTax = (23200 * 0.10) + (71100 * 0.12) + (106750 * 0.22) + (182850 * 0.24) + (103550 * 0.32) + ((annualFederalTaxableIncome – 487450) * 0.35);
} else {
federalTax = (23200 * 0.10) + (71100 * 0.12) + (106750 * 0.22) + (182850 * 0.24) + (103550 * 0.32) + (243750 * 0.35) + ((annualFederalTaxableIncome – 731200) * 0.37);
}
}
federalTax = (federalTax / payFrequency) + additionalFederalWithholding;
if (federalTax < 0) federalTax = 0; // Ensure tax is not negative
// 6. Calculate Total Deductions
var totalDeductions = preTaxDeductions + socialSecurityTax + medicareTax + coloradoStateTax + coloradoFamli + postTaxDeductions + additionalFederalWithholding;
// 7. Calculate Net Pay
var netPay = grossPay – totalDeductions;
// Display results
document.getElementById('grossPayOutput').innerText = '$' + grossPay.toFixed(2);
document.getElementById('preTaxDeductionsOutput').innerText = '$' + preTaxDeductions.toFixed(2);
document.getElementById('taxableGrossPayOutput').innerText = '$' + taxableGrossPayFICAStateFederal.toFixed(2);
document.getElementById('federalTaxOutput').innerText = '$' + federalTax.toFixed(2);
document.getElementById('socialSecurityTaxOutput').innerText = '$' + socialSecurityTax.toFixed(2);
document.getElementById('medicareTaxOutput').innerText = '$' + medicareTax.toFixed(2);
document.getElementById('coloradoStateTaxOutput').innerText = '$' + coloradoStateTax.toFixed(2);
document.getElementById('coloradoFamliOutput').innerText = '$' + coloradoFamli.toFixed(2);
document.getElementById('postTaxDeductionsOutput').innerText = '$' + postTaxDeductions.toFixed(2);
document.getElementById('netPayOutput').innerText = '$' + netPay.toFixed(2);
}
// Run calculation on page load with default values
window.onload = calculatePayroll;
.calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f9f9f9;
border: 1px solid #ddd;
border-radius: 8px;
padding: 25px;
max-width: 700px;
margin: 20px auto;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.calculator-container h2 {
color: #333;
text-align: center;
margin-bottom: 25px;
font-size: 28px;
}
.calculator-inputs .form-group {
margin-bottom: 18px;
display: flex;
flex-direction: column;
}
.calculator-inputs label {
font-weight: bold;
margin-bottom: 7px;
color: #555;
font-size: 15px;
}
.calculator-inputs input[type="number"],
.calculator-inputs select {
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 5px;
font-size: 16px;
width: 100%;
box-sizing: border-box; /* Include padding and border in the element's total width and height */
}
.calculator-inputs input[type="number"]:focus,
.calculator-inputs select:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}
.calculator-container button {
background-color: #007bff;
color: white;
padding: 12px 25px;
border: none;
border-radius: 5px;
font-size: 18px;
cursor: pointer;
display: block;
width: 100%;
margin-top: 25px;
transition: background-color 0.3s ease, transform 0.2s ease;
}
.calculator-container button:hover {
background-color: #0056b3;
transform: translateY(-1px);
}
.calculator-results {
background-color: #e9f7ff;
border: 1px solid #cce5ff;
border-radius: 8px;
padding: 20px;
margin-top: 30px;
}
.calculator-results h3 {
color: #0056b3;
margin-top: 0;
margin-bottom: 20px;
font-size: 22px;
text-align: center;
}
.calculator-results p {
display: flex;
justify-content: space-between;
padding: 8px 0;
border-bottom: 1px dashed #cce5ff;
margin: 0;
font-size: 16px;
}
.calculator-results p:last-of-type {
border-bottom: none;
}
.calculator-results p strong {
color: #333;
}
.calculator-results span {
color: #0056b3;
font-weight: bold;
}
.calculator-results .total-net-pay {
font-size: 20px;
padding-top: 15px;
border-top: 2px solid #007bff;
margin-top: 15px;
}
.calculator-results .total-net-pay strong,
.calculator-results .total-net-pay span {
color: #28a745; /* Green for net pay */
font-size: 22px;
}
Understanding Your Colorado Paycheck: A Comprehensive Guide
Navigating your paycheck can sometimes feel like deciphering a complex code. This Colorado Payroll Calculator is designed to help you understand how your gross earnings are transformed into your net take-home pay, considering federal and state taxes, as well as common deductions specific to Colorado.
How the Colorado Payroll Calculator Works
Our calculator takes your gross pay and pay frequency, then applies the relevant federal and Colorado-specific tax laws and deductions to estimate your net pay. It's important to note that while this calculator provides a robust estimate, individual circumstances (like specific tax credits, additional income, or complex deductions) can affect your actual paycheck. The federal income tax calculation is a simplified approximation based on standard deductions and tax brackets for the given filing status and does not account for all possible W-4 adjustments or tax credits beyond the standard deduction.
Key Components of Your Colorado Paycheck
1. Gross Pay
This is your total earnings before any taxes or deductions are withheld. It's the starting point for all payroll calculations.
2. Pre-Tax Deductions
These are deductions taken from your gross pay before taxes are calculated. Common examples include contributions to a 401(k) or 403(b) retirement plan, health insurance premiums, and Flexible Spending Account (FSA) contributions. Pre-tax deductions reduce your taxable income, meaning you pay less in federal, state, and sometimes FICA taxes.
3. Federal Income Tax Withholding
This is the amount withheld from your paycheck to cover your federal income tax liability. The amount depends on your gross pay, filing status (Single or Married Filing Jointly), and any additional withholding you've requested on your W-4 form. Our calculator uses a simplified method based on current tax brackets and standard deductions to estimate this amount.
4. FICA Taxes (Social Security and Medicare)
- Social Security Tax: This funds benefits for retirees, the disabled, and survivors. The employee contribution rate is 6.2% of your gross wages, up to an annual wage base limit ($168,600 for 2024).
- Medicare Tax: This funds hospital insurance for the elderly and disabled. The employee contribution rate is 1.45% of all your gross wages, with no wage base limit.
These taxes are mandatory federal payroll taxes.
5. Colorado State Income Tax
Colorado has a flat income tax rate. For 2024, the rate is 4.40% of your federal taxable income (after certain adjustments, but for simplicity in this calculator, it's applied to your gross pay minus pre-tax deductions). Unlike federal tax, Colorado does not have different tax brackets or filing statuses that significantly alter the rate for most taxpayers.
6. Colorado FAMLI Employee Contribution
Colorado's Family and Medical Leave Insurance (FAMLI) program provides paid leave benefits for qualifying life events. For 2024, the total premium rate is 0.9% of an employee's wages, with the employee typically contributing 0.45% (half of the total premium). This contribution is capped at the Social Security wage base ($168,600 for 2024).
7. Post-Tax Deductions
These are deductions taken from your pay *after* all applicable taxes have been calculated and withheld. Examples include Roth 401(k) contributions, garnishments, union dues, or certain charitable contributions.
8. Net Pay
This is your take-home pay – the amount you actually receive after all taxes and deductions have been subtracted from your gross pay.
Important Considerations
- Annual Adjustments: Tax rates, wage bases, and standard deductions are subject to change annually. This calculator uses 2024 figures.
- Specific Situations: This calculator provides an estimate. Your actual paycheck may vary due to factors like specific local taxes (if applicable), additional tax credits, or unique employer benefits.
- Professional Advice: For personalized tax advice or complex payroll situations, always consult with a qualified tax professional or financial advisor.