Calculating your net pay accurately involves understanding various deductions that are taken from your gross salary. This calculator helps you estimate your take-home pay after accounting for taxes and your 401k retirement savings contributions.
Key Components Explained:
Gross Pay: This is the total amount of money you earn before any deductions are taken out. It's your base salary or wages for a specific pay period.
401k Contribution: This is the amount you elect to contribute to your employer-sponsored 401k retirement savings plan. Contributions are typically made pre-tax, meaning they reduce your taxable income. The percentage you choose directly impacts your immediate take-home pay and your long-term retirement savings. There are annual limits set by the IRS for how much you can contribute.
Taxable Income: This is the portion of your gross income that is subject to income tax. In this calculator, we determine taxable income by subtracting your pre-tax 401k contributions from your gross pay.
Federal Tax: This is the income tax withheld by the U.S. federal government. The amount withheld depends on your taxable income, your filing status, and the tax bracket you fall into.
State Tax: Similar to federal tax, this is income tax withheld by your state government. Tax rates and rules vary significantly by state. Some states have no state income tax.
FICA Tax: This stands for the Federal Insurance Contributions Act. It covers Social Security and Medicare taxes. Both employees and employers contribute to these. The rate is fixed (currently 7.65% for employees, comprising 6.2% for Social Security up to an annual wage limit, and 1.45% for Medicare with no wage limit).
Total Deductions: This is the sum of all your pre-tax and post-tax deductions, including your 401k contributions, federal tax, state tax, and FICA taxes.
Net Pay: This is your "take-home pay" – the amount of money you actually receive after all deductions have been subtracted from your gross pay.
How the Calculation Works:
1. Calculate 401k Contribution: Gross Pay * (401k Contribution Rate / 100)
2. Calculate Taxable Income: Gross Pay – 401k Contribution
3. Calculate Federal Tax: Taxable Income * (Federal Tax Rate / 100)
4. Calculate State Tax: Taxable Income * (State Tax Rate / 100)
5. Calculate FICA Tax: Gross Pay * (FICA Tax Rate / 100) *(Note: FICA is typically calculated on gross pay, not taxable income after 401k contributions)*
6. Calculate Total Deductions: 401k Contribution + Federal Tax + State Tax + FICA Tax
7. Calculate Net Pay: Gross Pay – Total Deductions
Use Cases:
Budgeting: Understand how much money you'll actually have available to spend each pay period.
Financial Planning: Evaluate the impact of increasing or decreasing your 401k contribution rate on your take-home pay and retirement savings.
Salary Negotiation: Estimate the net pay from a proposed gross salary to ensure it meets your financial needs.
Understanding Pay Stubs: Cross-reference the calculator's results with your actual pay stub to ensure accuracy and understand deductions.
Disclaimer: This calculator provides an estimate based on the inputs provided. It does not account for all possible deductions (e.g., health insurance premiums, other retirement plans, garnishments, local taxes) and may not reflect the exact calculations of your employer's payroll system. Consult with your HR department or a tax professional for precise figures.
function calculatePayroll() {
var grossPay = parseFloat(document.getElementById("grossPay").value);
var fedTaxRate = parseFloat(document.getElementById("fedTaxRate").value);
var stateTaxRate = parseFloat(document.getElementById("stateTaxRate").value);
var ficaRate = parseFloat(document.getElementById("ficaRate").value);
var four01kRate = parseFloat(document.getElementById("four01kRate").value);
var resultGrossPayElement = document.getElementById("resultGrossPay");
var result401kContributionElement = document.getElementById("result401kContribution");
var resultTaxableIncomeElement = document.getElementById("resultTaxableIncome");
var resultFederalTaxElement = document.getElementById("resultFederalTax");
var resultStateTaxElement = document.getElementById("resultStateTax");
var resultFicaTaxElement = document.getElementById("resultFicaTax");
var resultTotalDeductionsElement = document.getElementById("resultTotalDeductions");
var resultNetPayElement = document.getElementById("resultNetPay");
// Clear previous results if inputs are invalid
resultGrossPayElement.textContent = "$0.00";
result401kContributionElement.textContent = "$0.00";
resultTaxableIncomeElement.textContent = "$0.00";
resultFederalTaxElement.textContent = "$0.00";
resultStateTaxElement.textContent = "$0.00";
resultFicaTaxElement.textContent = "$0.00";
resultTotalDeductionsElement.textContent = "$0.00";
resultNetPayElement.textContent = "$0.00";
if (isNaN(grossPay) || grossPay < 0 ||
isNaN(fedTaxRate) || fedTaxRate 100 ||
isNaN(stateTaxRate) || stateTaxRate 100 ||
isNaN(ficaRate) || ficaRate 100 ||
isNaN(four01kRate) || four01kRate 100) {
alert("Please enter valid positive numbers for all fields. Tax and contribution rates should be between 0 and 100.");
return;
}
var four01kContribution = grossPay * (four01kRate / 100);
var taxableIncome = grossPay – four01kContribution;
var federalTax = taxableIncome * (fedTaxRate / 100);
var stateTax = taxableIncome * (stateTaxRate / 100);
var ficaTax = grossPay * (ficaRate / 100); // FICA is typically based on gross pay
var totalDeductions = four01kContribution + federalTax + stateTax + ficaTax;
var netPay = grossPay – totalDeductions;
// Format currency and percentages
var formatCurrency = function(amount) {
return "$" + amount.toFixed(2);
};
resultGrossPayElement.textContent = formatCurrency(grossPay);
result401kContributionElement.textContent = formatCurrency(four01kContribution);
resultTaxableIncomeElement.textContent = formatCurrency(taxableIncome);
resultFederalTaxElement.textContent = formatCurrency(federalTax);
resultStateTaxElement.textContent = formatCurrency(stateTax);
resultFicaTaxElement.textContent = formatCurrency(ficaTax);
resultTotalDeductionsElement.textContent = formatCurrency(totalDeductions);
resultNetPayElement.textContent = formatCurrency(netPay);
}