function calculatePayroll() {
// Input values
var grossPayPerPeriod = parseFloat(document.getElementById("grossPayInput").value);
var payPeriodsPerYear = parseInt(document.getElementById("payFrequency").value);
var federalFilingStatus = document.getElementById("federalFilingStatus").value;
var federalDependents = parseInt(document.getElementById("federalDependents").value);
var preTax401k = parseFloat(document.getElementById("preTax401k").value);
var preTaxHealth = parseFloat(document.getElementById("preTaxHealth").value);
var otherPreTax = parseFloat(document.getElementById("otherPreTax").value);
var postTaxDeductions = parseFloat(document.getElementById("postTaxDeductions").value);
// Validate inputs
if (isNaN(grossPayPerPeriod) || grossPayPerPeriod < 0) grossPayPerPeriod = 0;
if (isNaN(federalDependents) || federalDependents < 0) federalDependents = 0;
if (isNaN(preTax401k) || preTax401k < 0) preTax401k = 0;
if (isNaN(preTaxHealth) || preTaxHealth < 0) preTaxHealth = 0;
if (isNaN(otherPreTax) || otherPreTax < 0) otherPreTax = 0;
if (isNaN(postTaxDeductions) || postTaxDeductions < 0) postTaxDeductions = 0;
// Constants for 2024 (simplified for calculator)
var socialSecurityRate = 0.062;
var socialSecurityWageBase = 168600; // Annual limit
var medicareRate = 0.0145;
var dependentCreditAmount = 2000; // Per dependent for W-4 Step 3
// Federal Income Tax Brackets (Annualized, 2024)
var federalTaxBrackets = {
'single': [
{ limit: 11600, rate: 0.10, base: 0 },
{ limit: 47150, rate: 0.12, base: 1160 },
{ limit: 100525, rate: 0.22, base: 5426 },
{ limit: 191950, rate: 0.24, base: 17167.50 },
{ limit: 243725, rate: 0.32, base: 39115.50 },
{ limit: 609350, rate: 0.35, base: 55267.50 },
{ limit: Infinity, rate: 0.37, base: 183362.50 }
],
'married': [
{ limit: 23200, rate: 0.10, base: 0 },
{ limit: 94300, rate: 0.12, base: 2320 },
{ limit: 201050, rate: 0.22, base: 10852 },
{ limit: 383900, rate: 0.24, base: 34335 },
{ limit: 487450, rate: 0.32, base: 78231 },
{ limit: 731200, rate: 0.35, base: 110535 },
{ limit: Infinity, rate: 0.37, base: 194832.50 }
]
};
// Standard Deduction for withholding (Annualized, 2024)
var standardDeduction = 0;
if (federalFilingStatus === 'single') {
standardDeduction = 14600;
} else if (federalFilingStatus === 'married') {
standardDeduction = 29200;
}
// Note: This calculator simplifies W-4 Step 4(b) "Deductions" to just the standard deduction.
// — Calculations —
// 1. Total Pre-Tax Deductions
var totalPreTaxDeductions = preTax401k + preTaxHealth + otherPreTax;
// 2. Taxable Gross for FICA and Federal Income Tax
var taxableGross = grossPayPerPeriod – totalPreTaxDeductions;
if (taxableGross < 0) taxableGross = 0; // Cannot be negative
// 3. Social Security Tax
var annualGrossForSS = grossPayPerPeriod * payPeriodsPerYear;
var annualPreTaxForSS = totalPreTaxDeductions * payPeriodsPerYear;
var annualTaxableForSS = annualGrossForSS – annualPreTaxForSS;
if (annualTaxableForSS < 0) annualTaxableForSS = 0;
var socialSecurityTax = 0;
if (annualTaxableForSS <= socialSecurityWageBase) {
socialSecurityTax = taxableGross * socialSecurityRate;
} else {
// If annual taxable gross exceeds wage base, need to calculate carefully.
// This simplified calculator assumes current period's taxable gross is subject to SS tax
// up to the remaining annual limit. A more complex system would track year-to-date.
// For simplicity, we'll apply the rate to the current period's taxable gross,
// but acknowledge that a real payroll system would stop withholding once the annual limit is met.
// For this calculator, we'll cap the *annual* SS tax, then divide by pay periods.
var annualSSTax = Math.min(annualTaxableForSS, socialSecurityWageBase) * socialSecurityRate;
socialSecurityTax = annualSSTax / payPeriodsPerYear;
}
// 4. Medicare Tax
var medicareTax = taxableGross * medicareRate; // No wage base limit
// 5. Federal Income Tax
var annualTaxableWagesForFIT = (grossPayPerPeriod * payPeriodsPerYear) – (totalPreTaxDeductions * payPeriodsPerYear);
if (annualTaxableWagesForFIT < 0) annualTaxableWagesForFIT = 0;
// Apply W-4 Step 4(b) Deductions (simplified to standard deduction)
var annualAmountSubjectToTax = annualTaxableWagesForFIT – standardDeduction;
if (annualAmountSubjectToTax < 0) annualAmountSubjectToTax = 0;
var annualFederalTax = 0;
var brackets = federalTaxBrackets[federalFilingStatus];
for (var i = 0; i bracket.limit) {
annualFederalTax = bracket.base + (bracket.limit – (i > 0 ? brackets[i-1].limit : 0)) * bracket.rate;
} else {
annualFederalTax = bracket.base + (annualAmountSubjectToTax – (i > 0 ? brackets[i-1].limit : 0)) * bracket.rate;
break;
}
}
// If annualAmountSubjectToTax is greater than the highest bracket limit, the loop will finish
// and annualFederalTax will be calculated based on the highest bracket.
if (annualAmountSubjectToTax > brackets[brackets.length – 2].limit) { // Check against second to last bracket limit
annualFederalTax = brackets[brackets.length – 1].base + (annualAmountSubjectToTax – brackets[brackets.length – 2].limit) * brackets[brackets.length – 1].rate;
}
// Apply W-4 Step 3 Dependent Credit
var totalDependentCredit = federalDependents * dependentCreditAmount;
annualFederalTax = annualFederalTax – totalDependentCredit;
if (annualFederalTax < 0) annualFederalTax = 0;
var federalIncomeTax = annualFederalTax / payPeriodsPerYear;
// 6. Tennessee State Income Tax (0% on wages)
var stateIncomeTax = 0;
// 7. Total Deductions
var totalDeductions = totalPreTaxDeductions + socialSecurityTax + medicareTax + federalIncomeTax + stateIncomeTax + postTaxDeductions;
// 8. Net Pay
var netPay = grossPayPerPeriod – totalDeductions;
// — Display Results —
document.getElementById("grossPayResult").innerText = "$" + grossPayPerPeriod.toFixed(2);
document.getElementById("totalPreTaxDeductionsResult").innerText = "$" + totalPreTaxDeductions.toFixed(2);
document.getElementById("taxableGrossResult").innerText = "$" + taxableGross.toFixed(2);
document.getElementById("socialSecurityTaxResult").innerText = "$" + socialSecurityTax.toFixed(2);
document.getElementById("medicareTaxResult").innerText = "$" + medicareTax.toFixed(2);
document.getElementById("federalIncomeTaxResult").innerText = "$" + federalIncomeTax.toFixed(2);
document.getElementById("stateIncomeTaxResult").innerText = "$" + stateIncomeTax.toFixed(2);
document.getElementById("totalDeductionsResult").innerText = "$" + totalDeductions.toFixed(2);
document.getElementById("netPayResult").innerText = "$" + netPay.toFixed(2);
}
// Run calculation on page load for initial values
window.onload = calculatePayroll;
Understanding Your Tennessee Paycheck
Navigating your payroll can sometimes feel complex, but with this Tennessee Payroll Calculator, you can get a clear estimate of your net pay. This tool helps you understand how various deductions impact your take-home earnings in the Volunteer State.
Key Components of Your Tennessee Paycheck
When you receive your paycheck in Tennessee, several factors contribute to the final amount you take home. Here's a breakdown of the main deductions and considerations:
1. Gross Pay
This is your total earnings before any deductions. It includes your regular wages, salary, commissions, bonuses, and any other compensation you receive from your employer.
2. Pre-Tax Deductions
These are deductions taken from your gross pay before taxes are calculated. Common pre-tax deductions include:
401(k) Contributions: Money you contribute to a retirement plan.
Health Insurance Premiums: Your share of the cost for employer-sponsored health coverage.
Flexible Spending Accounts (FSAs) or Health Savings Accounts (HSAs): Contributions to these accounts for healthcare expenses.
Pre-tax deductions reduce your taxable income, meaning you pay less in federal income tax and sometimes FICA taxes (depending on the deduction type).
3. Federal Taxes
These are mandatory deductions that go to the U.S. government:
Federal Income Tax: This is withheld based on the information you provide on your W-4 form (filing status, dependents, and other adjustments). The calculator uses simplified 2024 federal tax brackets and standard deductions to estimate this amount.
Social Security Tax (FICA): This is 6.2% of your gross pay, up to an annual wage base limit ($168,600 for 2024). Your employer also pays an equal amount.
Medicare Tax (FICA): This is 1.45% of your gross pay, with no wage base limit. There's an additional 0.9% Medicare tax for high earners, which this simplified calculator does not include. Your employer also pays an equal amount.
4. Tennessee State Income Tax
Good news for Tennessee residents: As of January 1, 2021, Tennessee does not levy a state income tax on wages. This means your paycheck will not have a deduction for state income tax, which can significantly increase your take-home pay compared to many other states. (Note: Tennessee previously had a "Hall Income Tax" on interest and dividends, but this has been fully phased out.)
5. Post-Tax Deductions
These deductions are taken from your pay after all applicable taxes have been calculated and withheld. Examples include:
Roth 401(k) Contributions: Unlike traditional 401(k)s, these are funded with after-tax dollars.
Garnishments: Court-ordered deductions for debts like child support or student loans.
Union Dues: Fees paid to a labor union.
Charitable Contributions: Donations made directly from your paycheck.
6. Net Pay
This is the final amount you receive after all pre-tax deductions, federal taxes, and post-tax deductions have been subtracted from your gross pay. It's your actual take-home pay.
How to Use the Calculator
Simply enter your gross pay per period, select your pay frequency, federal filing status, and number of dependents. Then, input any pre-tax or post-tax deductions you have. The calculator will instantly provide an estimate of your net pay, along with a detailed breakdown of all deductions.
Disclaimer: This calculator provides estimates for informational purposes only. Actual payroll deductions may vary based on specific tax laws, individual circumstances, and additional deductions not included in this simplified tool. Consult with a qualified financial or tax professional for personalized advice.