Estimate federal income tax, Social Security, and Medicare taxes withheld from your paycheck.
Weekly
Bi-Weekly
Semi-Monthly
Monthly
Single
Married Filing Jointly
Married Filing Separately
Head of Household
Your estimated total withholding will appear here.
Understanding Payroll Withholding
Payroll withholding is the process by which an employer deducts money from an employee's gross wages for various purposes, including income taxes, Social Security taxes, Medicare taxes, and other potential deductions like health insurance premiums or retirement contributions. The amount withheld directly impacts your net pay (take-home pay).
Key Components of Withholding:
Federal Income Tax: This is based on your gross pay, filing status (Single, Married Filing Jointly, etc.), number of allowances claimed on your W-4 form, and any additional amounts you've elected to withhold. The IRS uses tax tables and formulas to determine the appropriate withholding amount.
Social Security Tax: A fixed percentage (currently 6.2%) is applied to your gross wages up to an annual wage base limit ($168,600 for 2024). This tax funds retirement, disability, and survivor benefits. Both employer and employee contribute.
Medicare Tax: A fixed percentage (1.45%) is applied to all your gross wages. There is no wage base limit for Medicare tax. This tax funds the Medicare program, providing hospital insurance. Additional Medicare tax (0.9%) applies to high earners.
State and Local Income Tax: If applicable in your state or locality, these taxes are also withheld based on specific state/local rules and forms.
Other Deductions: This can include pre-tax deductions (like 401(k) contributions, health insurance premiums) which reduce your taxable income, and post-tax deductions.
How This Calculator Works:
This calculator provides an *estimate* of your federal income tax, Social Security, and Medicare withholding. It uses simplified logic based on common withholding practices:
Annualizing Income: Your gross pay per pay period is multiplied by the number of pay periods in a year based on your selected frequency (e.g., Weekly: 52, Bi-Weekly: 26, Semi-Monthly: 24, Monthly: 12).
Calculating Taxable Income: For income tax estimation, we subtract a portion of the standard deduction based on your filing status and the number of allowances claimed. The IRS provides an "adjusted wage" calculation for withholding. A simplified approach is often used where each allowance reduces taxable income by a certain amount (e.g., approx. $4,700 per allowance for Single filers in 2024, though this varies). This calculator uses a simplified factor based on allowances.
Applying Tax Brackets: The calculated annual taxable income is then subjected to estimated federal income tax rates for the corresponding filing status. (Note: This calculator uses simplified flat rate estimations for demonstration as actual IRS tables are complex and change).
Calculating FICA Taxes: Social Security tax is 6.2% on gross wages up to the annual limit. Medicare tax is 1.45% on all gross wages.
Adjusting for Pay Period: The calculated annual withholding amounts (income tax) and per-period FICA taxes are divided by the number of pay periods to estimate the withholding for the current pay period.
Additional Withholding: Any amount entered for "Additional Withholding" is added directly to the estimated total withholding.
Disclaimer: This calculator is for informational and estimation purposes only. It does not constitute professional tax advice. Actual withholding may vary based on specific IRS regulations, state/local laws, and your unique tax situation. Always consult your employer's payroll department or a qualified tax professional for precise figures and advice.
Use Cases:
Employees: To get a better understanding of how much tax is being withheld from each paycheck and to see how changes to your W-4 might affect your take-home pay.
HR/Payroll Professionals: As a quick tool to demonstrate withholding calculations to employees or to verify basic calculations.
Financial Planning: To help budget and forecast net income more accurately.
function calculateWithholding() {
var grossPay = parseFloat(document.getElementById("grossPay").value);
var payFrequency = document.getElementById("payFrequency").value;
var filingStatus = document.getElementById("filingStatus").value;
var allowances = parseInt(document.getElementById("allowances").value);
var additionalW4 = parseFloat(document.getElementById("additionalW4").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// — Input Validation —
if (isNaN(grossPay) || grossPay < 0) {
resultDiv.innerHTML = "Please enter a valid Gross Pay amount.";
return;
}
if (isNaN(allowances) || allowances < 0) {
resultDiv.innerHTML = "Please enter a valid number of Allowances.";
return;
}
if (isNaN(additionalW4) || additionalW4 < 0) {
resultDiv.innerHTML = "Please enter a valid Additional Withholding amount.";
return;
}
// — Constants and Assumptions (Simplified for demonstration) —
// These are simplified and do not reflect exact, current IRS tables which are complex and tiered.
// Actual tax brackets and standard deductions change annually.
var federalTaxRateEstimate = 0.15; // Simplified flat estimate for federal income tax rate
var socialSecurityRate = 0.062;
var medicareRate = 0.0145;
var socialSecurityWageBaseLimit = 168600; // Example for 2024, subject to change
var allowanceValue = 4700; // Simplified annual value per allowance (approx. for 2024, varies by status)
var payPeriodsPerYear;
switch (payFrequency) {
case "weekly":
payPeriodsPerYear = 52;
break;
case "bi-weekly":
payPeriodsPerYear = 26;
break;
case "semi-monthly":
payPeriodsPerYear = 24;
break;
case "monthly":
payPeriodsPerYear = 12;
break;
default:
payPeriodsPerYear = 52; // Default to weekly if unrecognized
}
var annualGrossPay = grossPay * payPeriodsPerYear;
var annualTaxableIncomeEstimate = annualGrossPay – (allowances * allowanceValue);
// Ensure taxable income doesn't go below zero
if (annualTaxableIncomeEstimate < 0) {
annualTaxableIncomeEstimate = 0;
}
// — Calculate Federal Income Tax (Simplified) —
// This is a highly simplified estimation. Real calculations use progressive tax brackets.
var estimatedAnnualFederalTax = annualTaxableIncomeEstimate * federalTaxRateEstimate;
var estimatedFederalTaxPerPeriod = estimatedAnnualFederalTax / payPeriodsPerYear;
// — Calculate Social Security Tax —
var socialSecurityTaxableWages = Math.min(annualGrossPay, socialSecurityWageBaseLimit);
var annualSocialSecurityTax = socialSecurityTaxableWages * socialSecurityRate;
var socialSecurityTaxPerPeriod = annualSocialSecurityTax / payPeriodsPerYear;
// — Calculate Medicare Tax —
var annualMedicareTax = annualGrossPay * medicareRate;
var medicareTaxPerPeriod = annualMedicareTax / payPeriodsPerYear;
// Note: Additional Medicare tax for high earners is not included in this simplified calculator.
// — Calculate Total Withholding —
var totalWithholdingPerPeriod = estimatedFederalTaxPerPeriod + socialSecurityTaxPerPeriod + medicareTaxPerPeriod + additionalW4;
// — Display Results —
var formattedGrossPay = grossPay.toFixed(2);
var formattedFederalTax = estimatedFederalTaxPerPeriod.toFixed(2);
var formattedSocialSecurity = socialSecurityTaxPerPeriod.toFixed(2);
var formattedMedicare = medicareTaxPerPeriod.toFixed(2);
var formattedTotalWithholding = totalWithholdingPerPeriod.toFixed(2);
var formattedNetPay = (grossPay – totalWithholdingPerPeriod).toFixed(2);
resultDiv.innerHTML = `
Estimated Withholding for This Pay Period:
Gross Pay: $${formattedGrossPay}
Estimated Federal Income Tax: $${formattedFederalTax}
Social Security Tax (${(socialSecurityRate * 100).toFixed(1)}%): $${formattedSocialSecurity}
Medicare Tax (${(medicareRate * 100).toFixed(2)}%): $${formattedMedicare}
Additional Withholding: $${additionalW4.toFixed(2)}Total Estimated Withholding: $${formattedTotalWithholding}
Estimated Net Pay: $${formattedNetPay}
(Based on simplified calculations. Consult official tax resources for accuracy.)
`;
}