Calculate Social Security and Medicare Withholdings
Single / Head of Household
Married Filing Jointly
Married Filing Separately
Results for this Pay Period
Social Security (6.2%):$0.00
Medicare (1.45%):$0.00
Additional Medicare (0.9%):$0.00
Total FICA Withholding:$0.00
How to Calculate FICA Tax: A Step-by-Step Guide
FICA stands for the Federal Insurance Contributions Act. It is a mandatory U.S. federal payroll tax that funds Social Security and Medicare. Both employees and employers contribute to these programs. Understanding how to calculate FICA ensures your paycheck withholdings are accurate and helps with personal financial planning.
1. The 2024 FICA Tax Rates
For most employees, the total FICA tax rate is 7.65% of gross wages. This is broken down into two parts:
Social Security Tax: 6.2% of gross pay.
Medicare Tax: 1.45% of gross pay.
Your employer matches these amounts, contributing an additional 7.65% on your behalf, totaling 15.3% contribution for your benefits.
2. Social Security Wage Base Limit
There is a cap on how much of your income is subject to Social Security tax. For 2024, the wage base limit is $168,600. Any earnings above this amount are not subject to the 6.2% Social Security tax.
3. Additional Medicare Tax
High earners are subject to an Additional Medicare Tax of 0.9%. This applies to earnings that exceed specific thresholds based on filing status:
Single / Head of Household: $200,000
Married Filing Jointly: $250,000
Married Filing Separately: $125,000
Example Calculation
If you earn $5,000 in a pay period and your Year-to-Date (YTD) earnings are $50,000:
Social Security: $5,000 × 0.062 = $310.00
Medicare: $5,000 × 0.0145 = $72.50
Total FICA: $310.00 + $72.50 = $382.50
function calculateFicaTax() {
// Get Input Values
var grossPay = parseFloat(document.getElementById('fica_gross_pay').value);
var ytdEarnings = parseFloat(document.getElementById('fica_ytd_earnings').value) || 0;
var filingStatus = document.getElementById('fica_filing_status').value;
if (isNaN(grossPay) || grossPay <= 0) {
alert("Please enter a valid gross pay amount.");
return;
}
// Constants for 2024
var ssRate = 0.062;
var mcRate = 0.0145;
var ssLimit = 168600;
var addMcRate = 0.009;
var addMcThreshold = 200000;
if (filingStatus === 'joint') {
addMcThreshold = 250000;
} else if (filingStatus === 'separate') {
addMcThreshold = 125000;
}
// 1. Calculate Social Security Tax
var taxableSS = 0;
if (ytdEarnings addMcThreshold) {
var amountSubjectToAddMc = 0;
if (ytdEarnings > addMcThreshold) {
// Entire current gross is above threshold
amountSubjectToAddMc = grossPay;
} else {
// Only portion of current gross is above threshold
amountSubjectToAddMc = newTotalYtd – addMcThreshold;
}
addMcTax = amountSubjectToAddMc * addMcRate;
}
// Totals
var totalFica = ssTax + mcTax + addMcTax;
// Update UI
document.getElementById('res_ss').innerText = "$" + ssTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('res_medicare').innerText = "$" + mcTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
var addMcRow = document.getElementById('additional_medicare_row');
if (addMcTax > 0) {
addMcRow.style.display = 'flex';
document.getElementById('res_add_medicare').innerText = "$" + addMcTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
} else {
addMcRow.style.display = 'none';
}
document.getElementById('res_total').innerText = "$" + totalFica.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Note for SS Cap
var note = "";
if (taxableSS < grossPay) {
note = "Note: Your Social Security tax was reduced because you reached the $168,600 wage base limit.";
}
document.getElementById('fica_note').innerText = note;
document.getElementById('fica_results').style.display = 'block';
}