Capital Gains Tax Estimator for Any Asset Sale
Capital Gains Tax Estimator
This calculator helps you estimate capital gains tax across one or more asset sales. You can add multiple transactions, apply fees, and estimate tax using separate rates for short-term and long-term holdings. Because capital gains rules vary widely across jurisdictions, the calculator is designed to be global by allowing you to configure the tax parameters directly.
What Is a Capital Gain?
A capital gain is the profit made when you sell an asset for more than your adjusted purchase cost. In simplified terms:
\( \text{Gain/Loss} = \text{Net Proceeds} - \text{Cost Basis} \)
Where:
\( \text{Net Proceeds} = (\text{Quantity} \times \text{Sell Price per Unit}) - \text{Sell Fees} \)
\( \text{Cost Basis} = (\text{Quantity} \times \text{Buy Price per Unit}) + \text{Buy Fees} \)
Short-Term vs Long-Term Holdings
Many tax systems apply different tax treatment depending on how long the asset was held. This estimator uses a configurable threshold (in days):
\[ \text{Holding Days} = \left\lfloor \frac{\text{Sell Date} - \text{Buy Date}}{1\ \text{day}} \right\rfloor \]
If holding days are at or above the threshold, the transaction is treated as long-term. Otherwise, it is treated as short-term.
Exemptions and Loss Offsets
Some jurisdictions provide an annual allowance or exemption that reduces taxable gains. This calculator applies a single configurable exemption amount to the combined gains after loss offsets:
\[ \text{Taxable Gains} = \max\left(0,\ (\text{Gains} - \text{Loss Offset}) - \text{Exemption}\right) \]
You can also limit how much of your losses may offset gains using the Loss offset percentage.
Estimated Tax Calculation
The calculator estimates tax by applying separate rates (plus an optional surcharge) to the taxable gains allocated between long-term and short-term transactions:
\[ \text{Estimated Tax} = \text{LT Taxable} \times r_{LT} + \text{ST Taxable} \times r_{ST} \]
Where \(r_{LT}\) and \(r_{ST}\) are rates expressed as decimals (for example, 15% is \(0.15\)). The Effective tax rate is:
\[ \text{Effective Rate} = \frac{\text{Estimated Tax}}{\text{Taxable Gains}} \times 100 \]
How to Use This Calculator
1. Choose a preset or set your own tax parameters (threshold, rates, exemption).
2. Enter one transaction and click Add transaction row to store it in the table.
3. Repeat for additional transactions.
4. Click Calculate to update the summary and table.
5. Use Customize Columns to reorder or hide columns, and export results to CSV/Excel.
Important Notes
This tool is an estimator. Real-world tax outcomes can depend on asset type, residency, tax year rules, inflation indexing, wash-sale rules, offsets beyond capital gains, and jurisdiction-specific thresholds. For accuracy, adjust the parameters to match your local rules and consult a qualified tax professional when needed.