function calculateMassachusettsPay() {
var grossSalary = parseFloat(document.getElementById('grossSalary').value) || 0;
var filingStatus = document.getElementById('filingStatus').value;
var monthlyPreTax = parseFloat(document.getElementById('preTaxDeductions').value) || 0;
var annualPreTax = monthlyPreTax * 12;
// 1. Adjusted Gross Income for Federal (simplified)
var taxableFederal = grossSalary – annualPreTax;
var standardDeduction = 14600; // 2024 Single
if (filingStatus === 'married') standardDeduction = 29200;
if (filingStatus === 'head') standardDeduction = 21900;
taxableFederal = Math.max(0, taxableFederal – standardDeduction);
// 2. Federal Income Tax Calculation (2024 Brackets Simplified)
var fedTax = 0;
if (filingStatus === 'single') {
if (taxableFederal > 609350) fedTax = 174238 + (taxableFederal – 609350) * 0.37;
else if (taxableFederal > 243725) fedTax = 47197 + (taxableFederal – 243725) * 0.35;
else if (taxableFederal > 191950) fedTax = 30649 + (taxableFederal – 191950) * 0.32;
else if (taxableFederal > 100525) fedTax = 14691 + (taxableFederal – 100525) * 0.24;
else if (taxableFederal > 47150) fedTax = 5147 + (taxableFederal – 47150) * 0.22;
else if (taxableFederal > 11600) fedTax = 1160 + (taxableFederal – 11600) * 0.12;
else fedTax = taxableFederal * 0.10;
} else if (filingStatus === 'married') {
if (taxableFederal > 731200) fedTax = 186854 + (taxableFederal – 731200) * 0.37;
else if (taxableFederal > 487450) fedTax = 101541 + (taxableFederal – 487450) * 0.35;
else if (taxableFederal > 383900) fedTax = 68445 + (taxableFederal – 383900) * 0.32;
else if (taxableFederal > 201050) fedTax = 24525 + (taxableFederal – 201050) * 0.24;
else if (taxableFederal > 94300) fedTax = 10294 + (taxableFederal – 94300) * 0.22;
else if (taxableFederal > 23200) fedTax = 2320 + (taxableFederal – 23200) * 0.12;
else fedTax = taxableFederal * 0.10;
} else { // Head of Household
if (taxableFederal > 609350) fedTax = 178051 + (taxableFederal – 609350) * 0.37;
else if (taxableFederal > 243700) fedTax = 51010 + (taxableFederal – 243700) * 0.35;
else if (taxableFederal > 191950) fedTax = 34450 + (taxableFederal – 191950) * 0.32;
else if (taxableFederal > 100500) fedTax = 12516 + (taxableFederal – 100500) * 0.24;
else if (taxableFederal > 63100) fedTax = 7210 + (taxableFederal – 63100) * 0.22;
else if (taxableFederal > 16550) fedTax = 1655 + (taxableFederal – 16550) * 0.12;
else fedTax = taxableFederal * 0.10;
}
// 3. FICA (Social Security 6.2% up to $168,600, Medicare 1.45%)
var ssTax = Math.min(grossSalary, 168600) * 0.062;
var medicareTax = grossSalary * 0.0145;
var ficaTotal = ssTax + medicareTax;
// 4. Massachusetts State Tax (Flat 5.0%)
// MA Personal Exemption (approx $4400 for single, $8800 for joint)
var maExemption = (filingStatus === 'married') ? 8800 : 4400;
var taxableMA = Math.max(0, grossSalary – annualPreTax – maExemption);
var stateTax = taxableMA * 0.05;
// 5. MA Paid Family and Medical Leave (PFML) – 2024 rate approx 0.318% for employee share
var pfml = grossSalary * 0.00318;
// 6. Final Calculations
var totalTax = fedTax + ficaTotal + stateTax + pfml;
var annualNet = grossSalary – totalTax – annualPreTax;
var monthlyNet = annualNet / 12;
var biWeeklyNet = annualNet / 26;
// Output formatting
document.getElementById('resFederalTax').innerText = '$' + fedTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resFica').innerText = '$' + ficaTotal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resStateTax').innerText = '$' + stateTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resPFML').innerText = '$' + pfml.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resAnnualNet').innerText = '$' + annualNet.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resMonthlyNet').innerText = '$' + monthlyNet.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resBiWeeklyNet').innerText = '$' + biWeeklyNet.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resultsArea').style.display = 'block';
}
Understanding Your Massachusetts Paycheck
Calculating take-home pay in the Commonwealth of Massachusetts involves several specific state-level deductions alongside federal taxes. While Massachusetts is known for its flat income tax rate, there are unique mandatory contributions like the Paid Family and Medical Leave (PFML) that employees must account for.
1. Massachusetts State Income Tax Rate
Massachusetts currently utilizes a flat income tax rate of 5.0%. Unlike the federal government's progressive tax brackets, every dollar of taxable income in MA is taxed at the same rate. However, residents are entitled to a personal exemption—typically $4,400 for single filers and $8,800 for married couples filing jointly—which reduces the total taxable amount.
2. Paid Family and Medical Leave (PFML)
Since 2019, Massachusetts has required most employees to contribute to the PFML program. For 2024, the total contribution rate is 0.88% of eligible wages, but this is split between the employer and the employee. The employee portion is generally 0.318% of gross pay. This fund provides temporary income replacement for workers taking leave for family or medical reasons.
3. Federal Taxes and FICA
Regardless of which state you live in, your paycheck will be subject to federal deductions:
Federal Income Tax: Based on your filing status and earnings level.
Social Security: 6.2% of your gross pay (up to the annual wage base limit).
Medicare: 1.45% of all gross earnings.
Example Calculation: $75,000 Salary
If you earn a gross salary of $75,000 per year as a single filer in Massachusetts with no pre-tax deductions:
Gross Monthly Pay: $6,250.00
Massachusetts State Tax (5%): ~$294.17 per month (after personal exemption)
PFML Contribution: ~$19.88 per month
FICA (SS + Medicare): ~$478.13 per month
Federal Income Tax: ~$580.00 per month
Estimated Monthly Take-Home: ~$4,877.82
Note: These figures are estimates based on standard 2024 tax data. Actual results may vary based on specific local taxes, additional exemptions, or voluntary deductions like 401(k) contributions and health insurance premiums.