Estimate your tax liability on asset sales based on your filing status and income.
Your income from wages, etc.
Single
Married Filing Jointly
Head of Household
Short Term (Less than 1 year)
Long Term (More than 1 year)
Please enter valid numbers for all fields.
Total Capital Gain:$0.00
Tax Classification:Long Term
Estimated Federal Tax:$0.00
Net Investment Income Tax (3.8%):$0.00
Effective Tax Rate:0%
Net Profit (After Tax):$0.00
function calculateCapitalGains() {
// Inputs
var purchasePrice = parseFloat(document.getElementById('purchasePrice').value);
var salePrice = parseFloat(document.getElementById('salePrice').value);
var annualIncome = parseFloat(document.getElementById('annualIncome').value);
var filingStatus = document.getElementById('filingStatus').value;
var holdingPeriod = document.getElementById('holdingPeriod').value;
var errorDisplay = document.getElementById('errorDisplay');
var resultsSection = document.getElementById('resultsSection');
// Validation
if (isNaN(purchasePrice) || isNaN(salePrice) || isNaN(annualIncome)) {
errorDisplay.style.display = 'block';
resultsSection.style.display = 'none';
return;
}
errorDisplay.style.display = 'none';
// Core Calc
var totalGain = salePrice – purchasePrice;
if (totalGain niitThreshold) {
var excessIncome = totalIncome – niitThreshold;
// Tax is applied to the lesser of the Gain or the Excess Income
var taxableNiitBase = Math.min(totalGain, excessIncome);
niitTax = taxableNiitBase * 0.038;
}
// Tax Bracket Logic
if (holdingPeriod === 'short') {
// Short Term: Taxed as Ordinary Income
// We calculate tax on (annualIncome + gain) minus tax on (annualIncome) to isolate tax on gain
federalTax = calculateOrdinaryTax(totalIncome, filingStatus) – calculateOrdinaryTax(annualIncome, filingStatus);
} else {
// Long Term: Preferential Rates (0%, 15%, 20%)
// The gain sits on TOP of the annual income in the stack
federalTax = calculateLongTermTax(annualIncome, totalGain, filingStatus);
}
var totalTaxLiability = federalTax + niitTax;
var netProfit = totalGain – totalTaxLiability;
var effectiveRate = (totalGain > 0) ? (totalTaxLiability / totalGain) * 100 : 0;
// Output
document.getElementById('resTotalGain').innerText = formatMoney(totalGain);
document.getElementById('resClass').innerText = (holdingPeriod === 'short') ? "Short Term (Ordinary Income)" : "Long Term (Capital Gains)";
document.getElementById('resFedTax').innerText = formatMoney(federalTax);
document.getElementById('resNiit').innerText = formatMoney(niitTax);
document.getElementById('resRate').innerText = effectiveRate.toFixed(2) + "%";
document.getElementById('resNetProfit').innerText = formatMoney(netProfit);
resultsSection.style.display = 'block';
}
// Helper: 2024 Ordinary Income Tax Brackets
function calculateOrdinaryTax(income, status) {
var tax = 0;
// Simplified 2024 Brackets for calculation structure
// Brackets: Rate, Single Limit, Married Limit, Head Limit
var brackets = [
{ rate: 0.10, single: 11600, married: 23200, head: 16550 },
{ rate: 0.12, single: 47150, married: 94300, head: 63100 },
{ rate: 0.22, single: 100525, married: 201050, head: 100500 },
{ rate: 0.24, single: 191950, married: 383900, head: 191950 },
{ rate: 0.32, single: 243725, married: 487450, head: 243700 },
{ rate: 0.35, single: 609350, married: 731200, head: 609350 },
{ rate: 0.37, single: Infinity, married: Infinity, head: Infinity }
];
var previousLimit = 0;
for (var i = 0; i previousLimit) {
var taxableAmount = Math.min(income, limit) – previousLimit;
tax += taxableAmount * brackets[i].rate;
}
previousLimit = limit;
}
return tax;
}
// Helper: 2024 Long Term Capital Gains Brackets
function calculateLongTermTax(baseIncome, gain, status) {
// Thresholds for 0%, 15%, 20%
// Single: 0-47025 (0%), 47026-518900 (15%), 518901+ (20%)
// Married: 0-94050 (0%), 94051-583750 (15%), 583751+ (20%)
// Head: 0-63000 (0%), 63001-551350 (15%), 551351+ (20%)
var t1 = 0; // 0% limit
var t2 = 0; // 15% limit
if (status === 'single') { t1 = 47025; t2 = 518900; }
else if (status === 'married') { t1 = 94050; t2 = 583750; }
else { t1 = 63000; t2 = 551350; }
var tax = 0;
var start = baseIncome;
var end = baseIncome + gain;
// Portion in 0% bucket
if (start t1) {
var s = Math.max(start, t1);
var e = Math.min(end, t2);
if (e > s) {
tax += (e – s) * 0.15;
}
}
// Portion in 20% bucket
if (end > t2) {
var s = Math.max(start, t2);
var amount = end – s;
tax += amount * 0.20;
}
return tax;
}
function formatMoney(amount) {
return '$' + amount.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
Understanding Capital Gains Tax in 2024
Calculating your capital gains tax liability is a critical step in financial planning, whether you are selling real estate, stocks, or a business. The tax you pay depends heavily on how long you held the asset and your overall income level.
Key Takeaway: The duration you hold an asset determines if you pay the lower long-term rates (0%, 15%, or 20%) or the higher short-term rates (based on your ordinary income tax bracket).
Short-Term vs. Long-Term Capital Gains
The IRS distinguishes between assets held for less than a year and those held for more than a year.
Short-Term Capital Gains: Assets held for one year or less. These are taxed as ordinary income, meaning they are added to your wages and taxed at your marginal tax rate, which can range from 10% to 37%.
Long-Term Capital Gains: Assets held for more than one year. These benefit from preferential tax rates, which are significantly lower than ordinary income rates for most taxpayers.
2024 Capital Gains Tax Brackets
For the 2024 tax year (taxes filed in 2025), the long-term capital gains rates are based on your taxable income and filing status:
Rate
Single
Married Filing Jointly
Head of Household
0%
Up to $47,025
Up to $94,050
Up to $63,000
15%
$47,026 – $518,900
$94,051 – $583,750
$63,001 – $551,350
20%
Over $518,900
Over $583,750
Over $551,350
What is the Net Investment Income Tax (NIIT)?
High-income earners may be subject to an additional 3.8% Net Investment Income Tax. This applies if your Modified Adjusted Gross Income (MAGI) exceeds the following thresholds:
$200,000 for Single or Head of Household filers
$250,000 for Married Filing Jointly
The calculator above automatically checks if your total income (Salary + Capital Gain) exceeds these limits and applies the 3.8% surtax to the applicable portion of your gain.
Strategies to Minimize Capital Gains Tax
There are several strategies investors use to reduce their tax burden:
Hold for over a year: The simplest way to reduce taxes is to wait at least a year and a day before selling, to qualify for long-term rates.
Tax-Loss Harvesting: You can offset capital gains by selling underperforming assets at a loss. Up to $3,000 of net losses can also offset ordinary income.
Use Tax-Advantaged Accounts: Trading within a 401(k) or IRA does not trigger immediate capital gains taxes.
Primary Residence Exclusion: If you sell your main home, you may exclude up to $250,000 (single) or $500,000 (married) of the gain from taxes, provided you lived there for two of the last five years.