Illinois Wage Calculator

Illinois Wage Calculator

function calculateIllinoisWage() { // Get input values var grossPay = parseFloat(document.getElementById("grossPay").value); var payFrequencyMultiplier = parseFloat(document.getElementById("payFrequency").value); var preTaxDeductions = parseFloat(document.getElementById("preTaxDeductions").value); var federalWithholding = parseFloat(document.getElementById("federalWithholding").value); var postTaxDeductions = parseFloat(document.getElementById("postTaxDeductions").value); // Validate inputs if (isNaN(grossPay) || grossPay < 0) { alert("Please enter a valid Gross Pay."); return; } if (isNaN(preTaxDeductions) || preTaxDeductions < 0) { preTaxDeductions = 0; // Default to 0 if invalid } if (isNaN(federalWithholding) || federalWithholding < 0) { federalWithholding = 0; // Default to 0 if invalid } if (isNaN(postTaxDeductions) || postTaxDeductions < 0) { postTaxDeductions = 0; // Default to 0 if invalid } // Constants for tax rates (2024 values) var SS_RATE = 0.062; var SS_WAGE_BASE_LIMIT = 168600; // Annual limit var MEDICARE_RATE = 0.0145; var IL_STATE_TAX_RATE = 0.0495; // — Calculations — // 1. Gross Annual Pay var annualGrossPay = grossPay * payFrequencyMultiplier; // 2. Taxable Gross for FICA and Illinois State Tax var taxableGrossForFICA_IL_perPeriod = Math.max(0, grossPay – preTaxDeductions); var annualTaxableGrossForFICA_IL = taxableGrossForFICA_IL_perPeriod * payFrequencyMultiplier; // 3. Social Security Tax var annualSSTaxable = Math.min(annualTaxableGrossForFICA_IL, SS_WAGE_BASE_LIMIT); var socialSecurityTax = (annualSSTaxable * SS_RATE) / payFrequencyMultiplier; // Ensure SS tax doesn't exceed the per-period portion of the annual limit if gross is very high socialSecurityTax = Math.min(socialSecurityTax, (SS_WAGE_BASE_LIMIT * SS_RATE) / payFrequencyMultiplier); // 4. Medicare Tax var medicareTax = (annualTaxableGrossForFICA_IL * MEDICARE_RATE) / payFrequencyMultiplier; // 5. Illinois State Income Tax var illinoisStateTax = taxableGrossForFICA_IL_perPeriod * IL_STATE_TAX_RATE; // 6. Federal Income Tax (taken directly from input) var federalIncomeTax = federalWithholding; // 7. Total Taxes var totalTaxes = socialSecurityTax + medicareTax + illinoisStateTax + federalIncomeTax; // 8. Total Deductions var totalDeductions = preTaxDeductions + totalTaxes + postTaxDeductions; // 9. Net Pay var netPay = grossPay – totalDeductions; // — Display Results — document.getElementById("displayGrossPay").innerText = "$" + grossPay.toFixed(2); document.getElementById("displayPreTaxDeductions").innerText = "$" + preTaxDeductions.toFixed(2); document.getElementById("displayTaxableGross").innerText = "$" + taxableGrossForFICA_IL_perPeriod.toFixed(2); document.getElementById("displaySSTax").innerText = "$" + socialSecurityTax.toFixed(2); document.getElementById("displayMedicareTax").innerText = "$" + medicareTax.toFixed(2); document.getElementById("displayILTax").innerText = "$" + illinoisStateTax.toFixed(2); document.getElementById("displayFederalTax").innerText = "$" + federalIncomeTax.toFixed(2); document.getElementById("displayTotalTaxes").innerText = "$" + totalTaxes.toFixed(2); document.getElementById("displayPostTaxDeductions").innerText = "$" + postTaxDeductions.toFixed(2); document.getElementById("displayNetPay").innerText = "$" + netPay.toFixed(2); } // Run calculation on page load with default values window.onload = calculateIllinoisWage;

Understanding Your Illinois Paycheck

Navigating your paycheck can sometimes feel like deciphering a complex code. Our Illinois Wage Calculator is designed to help you understand how your gross pay translates into your net take-home pay, considering federal, state, and common deductions specific to Illinois.

How Illinois Income Tax Works

Unlike many states that use progressive tax brackets, Illinois has a flat income tax rate. For 2024, the Illinois state income tax rate is 4.95% of your taxable income. This means that everyone pays the same percentage, regardless of how much they earn. Your taxable income for Illinois state tax purposes is generally your gross pay minus any pre-tax deductions (like 401k contributions or health insurance premiums).

Federal Taxes and Deductions

Your paycheck will also include federal deductions, primarily:

• Federal Income Tax: This is withheld based on the information you provide on your W-4 form (filing status, dependents, additional withholding). The calculator asks for an estimated amount per pay period, as accurately calculating this without full tax tables and personal circumstances is complex.
• FICA Taxes (Social Security and Medicare): These are mandatory federal taxes that fund Social Security and Medicare benefits.
  • Social Security: For 2024, the rate is 6.2% of your gross wages, up to an annual wage base limit of $168,600. Once your annual earnings exceed this limit, you no longer pay Social Security tax for the remainder of the year.
  • Medicare: The rate is 1.45% of all your gross wages, with no income limit. There's an additional Medicare tax of 0.9% on earnings above certain thresholds, which this basic calculator does not include for simplicity.

Pre-Tax vs. Post-Tax Deductions

• Pre-Tax Deductions: These are deductions taken from your gross pay BEFORE taxes are calculated. Common examples include contributions to a traditional 401(k), health insurance premiums, and Flexible Spending Accounts (FSAs). These deductions reduce your taxable income, meaning you pay less in federal, state, and sometimes FICA taxes.
• Post-Tax Deductions: These are deductions taken AFTER all applicable taxes have been calculated and withheld. Examples include Roth 401(k) contributions, union dues, charitable contributions, or wage garnishments. These do not reduce your taxable income.

Example Calculation

Let's use the default values in the calculator to illustrate:

• Gross Pay per Pay Period: $2,500 (Bi-weekly)
• Pre-Tax Deductions: $200 (e.g., health insurance, 401k)
• Estimated Federal Withholding: $300
• Post-Tax Deductions: $50 (e.g., union dues)

Here's how the calculation breaks down:

1. Taxable Gross (for FICA/IL): $2,500 (Gross) – $200 (Pre-Tax) = $2,300
2. Social Security Tax: ($2,300 * 26 annual periods) = $59,800 annual taxable. Since this is below the $168,600 limit, the full amount is taxed. ($59,800 * 0.062) / 26 = $142.60
3. Medicare Tax: ($2,300 * 26 annual periods) = $59,800 annual taxable. ($59,800 * 0.0145) / 26 = $33.35
4. Illinois State Income Tax: $2,300 (Taxable Gross) * 0.0495 = $113.85
5. Federal Income Tax: $300 (as entered)
6. Total Taxes: $142.60 (SS) + $33.35 (Medicare) + $113.85 (IL) + $300 (Federal) = $589.80
7. Total Deductions: $200 (Pre-Tax) + $589.80 (Taxes) + $50 (Post-Tax) = $839.80
8. Net Pay: $2,500 (Gross) – $839.80 (Total Deductions) = $1,660.20

This calculator provides an estimate. Your actual paycheck may vary slightly due to rounding, specific employer deductions, or other factors not included in this simplified calculation. Always refer to your official pay stubs for precise figures.