Illinois Paycheck Calculator
Use this calculator to estimate your net pay per pay period in Illinois, taking into account federal, state, and FICA taxes, as well as common deductions. Illinois has a flat income tax rate, making state tax calculations straightforward.
Paycheck Summary
Enter your details and click "Calculate Paycheck" to see your estimated earnings.
function calculatePaycheck() {
var grossPay = parseFloat(document.getElementById('grossPay').value);
var payFrequency = parseInt(document.getElementById('payFrequency').value);
var federalFilingStatus = document.getElementById('federalFilingStatus').value;
var numDependents = parseInt(document.getElementById('numDependents').value);
var otherDependents = parseInt(document.getElementById('otherDependents').value);
var extraFederalWithholding = parseFloat(document.getElementById('extraFederalWithholding').value);
var ilAllowances = parseInt(document.getElementById('ilAllowances').value);
var preTaxDeductions = parseFloat(document.getElementById('preTaxDeductions').value);
var postTaxDeductions = parseFloat(document.getElementById('postTaxDeductions').value);
// Validate inputs
if (isNaN(grossPay) || grossPay < 0) { grossPay = 0; }
if (isNaN(numDependents) || numDependents < 0) { numDependents = 0; }
if (isNaN(otherDependents) || otherDependents < 0) { otherDependents = 0; }
if (isNaN(extraFederalWithholding) || extraFederalWithholding < 0) { extraFederalWithholding = 0; }
if (isNaN(ilAllowances) || ilAllowances < 0) { ilAllowances = 0; }
if (isNaN(preTaxDeductions) || preTaxDeductions < 0) { preTaxDeductions = 0; }
if (isNaN(postTaxDeductions) || postTaxDeductions < 0) { postTaxDeductions = 0; }
var annualGrossPay = grossPay * payFrequency;
var annualPreTaxDeductions = preTaxDeductions * payFrequency;
// — FICA Taxes (Social Security & Medicare) —
var socialSecurityRate = 0.062;
var socialSecurityWageLimit = 168600; // 2024 limit
var medicareRate = 0.0145;
var ficaTaxableGross = grossPay – preTaxDeductions;
if (ficaTaxableGross < 0) ficaTaxableGross = 0;
var socialSecurityTax = 0;
if (annualGrossPay <= socialSecurityWageLimit) {
socialSecurityTax = ficaTaxableGross * socialSecurityRate;
} else if ((annualGrossPay – grossPay) < socialSecurityWageLimit) {
// If this pay period pushes annual gross over the limit
var taxableForSS = socialSecurityWageLimit – (annualGrossPay – grossPay);
socialSecurityTax = taxableForSS * socialSecurityRate;
}
// Note: This simplified SS calculation assumes current pay period doesn't exceed limit if previous periods didn't.
// A more robust calculation would track year-to-date earnings. For a single-period calculator, this is a common approximation.
var medicareTax = ficaTaxableGross * medicareRate;
// — Illinois State Income Tax —
var ilTaxRate = 0.0495; // 4.95%
var ilExemptionAmount = 2550; // 2024 per allowance
var annualIlTaxableIncome = annualGrossPay – annualPreTaxDeductions – (ilAllowances * ilExemptionAmount);
if (annualIlTaxableIncome < 0) annualIlTaxableIncome = 0;
var annualIlTax = annualIlTaxableIncome * ilTaxRate;
var ilStateTax = annualIlTax / payFrequency;
if (ilStateTax < 0) ilStateTax = 0; // Cannot have negative tax
// — Federal Income Tax (Simplified 2024 Brackets) —
var standardDeduction;
var childTaxCredit = numDependents * 2000; // Up to $2000 per qualifying child
var otherDependentCredit = otherDependents * 500; // Up to $500 per other dependent
if (federalFilingStatus === 'single') {
standardDeduction = 14600;
} else { // married
standardDeduction = 29200;
}
var annualFederalTaxableIncome = annualGrossPay – annualPreTaxDeductions – standardDeduction;
if (annualFederalTaxableIncome < 0) annualFederalTaxableIncome = 0;
var annualFederalTax = 0;
if (federalFilingStatus === 'single') {
if (annualFederalTaxableIncome <= 11600) {
annualFederalTax = annualFederalTaxableIncome * 0.10;
} else if (annualFederalTaxableIncome <= 47150) {
annualFederalTax = 1160 + (annualFederalTaxableIncome – 11600) * 0.12;
} else if (annualFederalTaxableIncome <= 100525) {
annualFederalTax = 5426 + (annualFederalTaxableIncome – 47150) * 0.22;
} else if (annualFederalTaxableIncome <= 191950) {
annualFederalTax = 17167.50 + (annualFederalTaxableIncome – 100525) * 0.24;
} else if (annualFederalTaxableIncome <= 243725) {
annualFederalTax = 39115.50 + (annualFederalTaxableIncome – 191950) * 0.32;
} else if (annualFederalTaxableIncome <= 609350) {
annualFederalTax = 55678.50 + (annualFederalTaxableIncome – 243725) * 0.35;
} else {
annualFederalTax = 183647.25 + (annualFederalTaxableIncome – 609350) * 0.37;
}
} else { // married
if (annualFederalTaxableIncome <= 23200) {
annualFederalTax = annualFederalTaxableIncome * 0.10;
} else if (annualFederalTaxableIncome <= 94300) {
annualFederalTax = 2320 + (annualFederalTaxableIncome – 23200) * 0.12;
} else if (annualFederalTaxableIncome <= 201050) {
annualFederalTax = 10852 + (annualFederalTaxableIncome – 94300) * 0.22;
} else if (annualFederalTaxableIncome <= 383900) {
annualFederalTax = 34337 + (annualFederalTaxableIncome – 201050) * 0.24;
} else if (annualFederalTaxableIncome <= 487450) {
annualFederalTax = 78221 + (annualFederalTaxableIncome – 383900) * 0.32;
} else if (annualFederalTaxableIncome <= 731200) {
annualFederalTax = 111357 + (annualFederalTaxableIncome – 487450) * 0.35;
} else {
annualFederalTax = 195804.50 + (annualFederalTaxableIncome – 731200) * 0.37;
}
}
// Apply credits
annualFederalTax -= (childTaxCredit + otherDependentCredit);
if (annualFederalTax < 0) annualFederalTax = 0; // Tax cannot be negative
var federalIncomeTax = (annualFederalTax / payFrequency) + extraFederalWithholding;
if (federalIncomeTax < 0) federalIncomeTax = 0; // Withholding cannot be negative
// — Total Deductions —
var totalDeductions = federalIncomeTax + socialSecurityTax + medicareTax + ilStateTax + preTaxDeductions + postTaxDeductions;
// — Net Pay —
var netPay = grossPay – totalDeductions;
// Display Results
var resultsHtml = `
Gross Pay: $${grossPay.toFixed(2)}
— Deductions —
Federal Income Tax: $${federalIncomeTax.toFixed(2)}
Social Security Tax: $${socialSecurityTax.toFixed(2)}
Medicare Tax: $${medicareTax.toFixed(2)}
Illinois State Tax: $${ilStateTax.toFixed(2)}
Pre-Tax Deductions: $${preTaxDeductions.toFixed(2)}
Post-Tax Deductions: $${postTaxDeductions.toFixed(2)}
Total Deductions: $${totalDeductions.toFixed(2)}
— Net Pay —
Net Pay: $${netPay.toFixed(2)}
`;
document.getElementById('result').innerHTML = resultsHtml;
}
.calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f9f9f9;
padding: 25px;
border-radius: 10px;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
max-width: 700px;
margin: 30px auto;
border: 1px solid #e0e0e0;
}
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text-align: center;
margin-bottom: 25px;
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line-height: 1.6;
margin-bottom: 10px;
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margin-bottom: 15px;
display: flex;
flex-direction: column;
}
.calc-form label {
margin-bottom: 7px;
font-weight: bold;
color: #333;
font-size: 0.95em;
}
.calc-form input[type="number"],
.calc-form select {
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 5px;
font-size: 1em;
width: 100%;
box-sizing: border-box;
transition: border-color 0.3s ease;
}
.calc-form input[type="number"]:focus,
.calc-form select:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 5px rgba(0, 123, 255, 0.2);
}
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background-color: #007bff;
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border: none;
border-radius: 5px;
font-size: 1.1em;
cursor: pointer;
margin-top: 20px;
width: 100%;
box-sizing: border-box;
transition: background-color 0.3s ease, transform 0.2s ease;
}
.calc-form button:hover {
background-color: #0056b3;
transform: translateY(-2px);
}
.calc-results {
background-color: #e9f7ef;
border: 1px solid #d4edda;
border-radius: 8px;
padding: 20px;
margin-top: 30px;
}
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color: #28a745;
text-align: center;
margin-bottom: 15px;
font-size: 1.5em;
}
.calc-results #result p {
font-size: 1.1em;
color: #333;
margin-bottom: 8px;
display: flex;
justify-content: space-between;
padding: 2px 0;
border-bottom: 1px dashed #e0e0e0;
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border-bottom: none;
margin-top: 15px;
font-size: 1.2em;
font-weight: bold;
color: #007bff;
}
.calc-results #result p strong {
color: #2c3e50;
}
@media (max-width: 600px) {
.calculator-container {
padding: 15px;
margin: 20px auto;
}
.calculator-container h2 {
font-size: 1.5em;
}
.calc-form label,
.calc-form input[type="number"],
.calc-form select,
.calc-form button {
font-size: 0.9em;
padding: 10px;
}
.calc-results #result p {
font-size: 1em;
}
}
Understanding Your Illinois Paycheck
Navigating your paycheck can sometimes feel like deciphering a complex code. For residents of Illinois, understanding the various deductions, especially state taxes, is crucial for financial planning. This Illinois Paycheck Calculator is designed to demystify your earnings, providing a clear estimate of your net pay after all federal, state, and other common deductions.
How Illinois State Tax Works
One of the defining characteristics of Illinois's tax system is its flat income tax rate. As of 2024, the state income tax rate is 4.95%. This means that, unlike the federal system which uses progressive tax brackets, everyone in Illinois pays the same percentage of their taxable income to the state, regardless of how much they earn. However, Illinois does allow for personal exemptions, which reduce your taxable income. For 2024, each allowance claimed on your Illinois W-4 reduces your annual taxable income by $2,550.
Key Components of Your Illinois Paycheck
Your gross pay is the total amount you earn before any deductions. From this, several amounts are withheld:
1. Federal Income Tax
This is a progressive tax, meaning higher earners pay a larger percentage of their income. The amount withheld depends on your gross pay, filing status (Single, Married Filing Jointly), and any credits or extra withholding you claim on your federal W-4 form. Our calculator uses simplified 2024 federal tax brackets and standard deductions to estimate this amount.
2. FICA Taxes (Social Security and Medicare)
- Social Security: This tax funds benefits for retirees, the disabled, and survivors. The rate is 6.2% of your gross wages, up to an annual wage limit ($168,600 for 2024).
- Medicare: This tax funds health insurance for the elderly and disabled. The rate is 1.45% of all your gross wages, with no income limit.
These taxes are mandatory federal deductions.
3. Illinois State Income Tax
As mentioned, this is a flat 4.95% of your taxable income. Your taxable income for state purposes is generally your gross pay minus any pre-tax deductions and your Illinois personal exemptions.
4. 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 for federal, state, and FICA taxes, leading to a lower overall tax burden.
5. Post-Tax Deductions
These deductions are taken from your pay after taxes have been calculated and withheld. Examples include Roth 401(k) contributions, union dues, charitable contributions, or garnishments. Post-tax deductions do not reduce your taxable income.
How to Use the Calculator
- Gross Pay per Pay Period: Enter your total earnings for one pay period before any deductions.
- Pay Frequency: Select how often you get paid (e.g., weekly, bi-weekly, monthly).
- Federal Filing Status: Choose your federal tax filing status (Single or Married Filing Jointly).
- Number of Qualifying Children: Enter the number of children under 17 you claim for the Child Tax Credit.
- Number of Other Dependents: Enter the number of other dependents you claim for the Credit for Other Dependents.
- Extra Federal Withholding: If you want an additional amount withheld for federal taxes each period, enter it here.
- Number of Illinois Allowances: Enter the number of allowances you claim on your Illinois W-4.
- Pre-Tax Deductions: Input the total amount of pre-tax deductions per pay period (e.g., 401k, health insurance).
- Post-Tax Deductions: Input the total amount of post-tax deductions per pay period (e.g., Roth 401k, union dues).
Click "Calculate Paycheck" to see a detailed breakdown of your estimated gross pay, all deductions, and your final net pay.
Disclaimer
This calculator provides an estimate based on the information you provide and current tax laws (2024). It does not account for all possible scenarios, such as additional Medicare tax, local taxes (Illinois does not have local income taxes), specific employer benefits, or complex tax situations. For precise figures, consult your payroll department or a qualified tax professional.