function calculateIdahoPaycheck() {
var grossInput = parseFloat(document.getElementById("grossPay").value) || 0;
var frequency = parseFloat(document.getElementById("payFrequency").value);
var filingStatus = document.getElementById("filingStatus").value;
var preTax = parseFloat(document.getElementById("preTaxDeductions").value) || 0;
// Annualize Gross Pay
var annualGross = (frequency === 1) ? grossInput : grossInput * frequency;
var annualPreTax = (frequency === 1) ? preTax : preTax * frequency;
var annualTaxableBase = annualGross – annualPreTax;
// 2024 Standard Deductions
var standardDeduction = (filingStatus === "single") ? 14600 : 29200;
// FICA Calculation (7.65%)
var ficaRate = 0.0765;
var annualFICA = annualGross * ficaRate;
// Federal Income Tax Brackets (Simplified 2024 Single/Married)
var fedTaxable = annualTaxableBase – standardDeduction;
if (fedTaxable 609350) annualFedTax += (fedTaxable – 609350) * 0.37 + 183647;
else if (fedTaxable > 243725) annualFedTax += (fedTaxable – 243725) * 0.35 + 55678;
else if (fedTaxable > 191950) annualFedTax += (fedTaxable – 191950) * 0.32 + 39110;
else if (fedTaxable > 100525) annualFedTax += (fedTaxable – 100525) * 0.24 + 17168;
else if (fedTaxable > 47150) annualFedTax += (fedTaxable – 47150) * 0.22 + 5404;
else if (fedTaxable > 11600) annualFedTax += (fedTaxable – 11600) * 0.12 + 1160;
else annualFedTax += fedTaxable * 0.10;
} else {
if (fedTaxable > 731200) annualFedTax += (fedTaxable – 731200) * 0.37 + 186662;
else if (fedTaxable > 487450) annualFedTax += (fedTaxable – 487450) * 0.35 + 101350;
else if (fedTaxable > 383900) annualFedTax += (fedTaxable – 383900) * 0.32 + 68224;
else if (fedTaxable > 201050) annualFedTax += (fedTaxable – 201050) * 0.24 + 24330;
else if (fedTaxable > 94300) annualFedTax += (fedTaxable – 94300) * 0.22 + 10808;
else if (fedTaxable > 23200) annualFedTax += (fedTaxable – 23200) * 0.12 + 2320;
else annualFedTax += fedTaxable * 0.10;
}
// Idaho State Tax – 5.8% Flat Tax on Income exceeding Federal Standard Deduction
var stateTaxable = annualTaxableBase – standardDeduction;
if (stateTaxable < 0) stateTaxable = 0;
var annualStateTax = stateTaxable * 0.058;
// Total Annual Net
var annualNet = annualGross – (annualFedTax + annualFICA + annualStateTax + annualPreTax);
// Show Results per Pay Period
var periodNet = annualNet / frequency;
var periodFedTax = annualFedTax / frequency;
var periodFica = annualFICA / frequency;
var periodStateTax = annualStateTax / frequency;
var totalDeductions = (annualFedTax + annualFICA + annualStateTax + annualPreTax) / frequency;
document.getElementById("netPayResult").innerText = "$" + periodNet.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("fedTaxResult").innerText = "$" + periodFedTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("ficaResult").innerText = "$" + periodFica.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("stateTaxResult").innerText = "$" + periodStateTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalDeductionsResult").innerText = "$" + totalDeductions.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resultsArea").style.display = "block";
}
Understanding Idaho Income Tax and Your Paycheck
If you live and work in the Gem State, understanding your take-home pay requires looking at federal taxes, FICA, and Idaho's unique tax landscape. Recently, Idaho has transitioned to a flat income tax rate, simplifying the process for residents compared to the previous graduated bracket system.
How Idaho Payroll Taxes Work
When you receive a paycheck in Idaho, several different entities take a "slice" of your gross earnings before you see the final amount in your bank account:
Federal Income Tax: This is calculated based on your filing status and taxable income after subtracting the standard deduction.
FICA (Federal Insurance Contributions Act): This includes Social Security (6.2%) and Medicare (1.45%), totaling 7.65% of your gross pay.
Idaho State Tax: Idaho currently uses a flat tax rate of 5.8%. This applies to your income that exceeds the federal standard deduction.
Pre-tax Deductions: These include contributions to 401(k) plans or health insurance premiums which reduce your taxable income.
Example: Idaho Paycheck Calculation
Let's look at a realistic example for a single person living in Boise earning a gross salary of $60,000 per year paid monthly.
Category
Amount (Annual)
Gross Annual Pay
$60,000.00
Standard Deduction (Single)
-$14,600.00
FICA Taxes (7.65%)
-$4,590.00
Idaho State Tax (5.8% of taxable)
-$2,633.20
Federal Income Tax (Estimated)
-$5,212.00
Total Annual Net Pay
$47,564.80
Monthly Take-Home
$3,963.73
Key Idaho Tax Facts
Idaho has become one of the most tax-friendly states in the Pacific Northwest due to recent reforms. Unlike neighboring Oregon (graduated high rates) or Washington (no state income tax but high sales tax), Idaho strikes a balance with its flat income tax rate of 5.8%.
Did you know? Idaho also offers a grocery tax credit for most residents, which can help offset some of the sales tax paid on food throughout the year, further increasing your actual "effective" take-home value.
Disclaimer: This calculator provides an estimate based on standard 2024 federal and state tax rules. It does not account for specific credits like the Child Tax Credit, specific local taxes, or voluntary payroll deductions like union dues or life insurance. Consult a tax professional for exact filing advice.