Capital gains tax in Thailand: a simple way to estimate it

Published May 29, 2026 · 2 min read

How to estimate capital gains tax on shares, property or other assets sold in Thailand: gain, costs, rate and net proceeds.

Working out the gain

The taxable gain is usually the sale price minus the purchase price and allowable costs, such as broker fees, legal fees or improvement costs. If the result is negative, you have a loss, which may be offset against other gains depending on the rules in Thailand.

Worked example

Here is the calculation with sample figures. Change any number in the Thailand Capital Gains Tax Calculator to run your own.

Rates, allowances and holding periods

Many countries tax gains at a different rate from salary, offer an annual tax-free allowance, or reduce the rate for assets held longer. Some exempt a main home. Because these rules differ so widely, the calculator uses an editable rate that you can set from current guidance in Thailand.

Keep the paperwork

Keep purchase contracts, statements and receipts for costs. Without them, proving your cost basis can be difficult years later.

Quick reference at 7%

Common amounts in Thailand, worked both ways: adding tax to a net price, and extracting it from a price that already includes tax.

How Thailand compares

Standard rates on file for other countries. A difference of a few points matters most on high-value purchases and on cross-border sales.

Using the calculator step by step

1. Open the Thailand Capital Gains Tax Calculator.
2. Type your figures into the numbered lines. Results update as you type.
3. Check the rate field. It starts at 7%; change it if a reduced rate, local surcharge or exemption applies to you.
4. Read the result on the receipt panel, and use the formula shown under it if you need to explain the figure to a client or colleague.

Key terms

Deduction

An amount subtracted from taxable income. It saves tax equal to the deduction times your marginal rate.

Gross amount

The amount after tax is added, which is usually what a consumer pays.

Marginal rate

The rate applied to the next unit of income. It decides how much of a raise or a deduction you keep.

Taxable income

Income left after allowances and deductions, on which the tax rates are applied.

Zero rate

A rate of 0% on a taxable supply. Unlike an exemption, the seller can usually still reclaim tax on costs.

Common mistakes to avoid

• Forgetting to deduct buying and selling costs.
• Ignoring an annual allowance or holding-period relief.
• Not keeping records of the original purchase price.

Frequently asked questions

This article is general information for planning, not tax advice. Rates and rules change; confirm with your tax authority or a qualified adviser.