How tax on a 40,000 baht salary is worked out
A monthly salary of 40,000 baht is 480,000 baht a year, but tax is not charged on the full 480,000 baht. Expenses and allowances come off first, and progressive rates are then applied to what is left.
| Annual income (40,000 × 12) | 480,000 |
|---|---|
| Less expenses: 50%, capped at 100,000 | − 100,000 |
| Less personal allowance 60,000 + social security 10,500 | − 70,500 |
| Net taxable income | 309,500 |
| Tax for the year | 8,450 |
| Average per month | 704 |
Tax in each bracket for a 40,000 baht salary
| Net taxable income (THB) | Rate | Income in bracket | Tax |
|---|---|---|---|
| 0– | exempt | 150,000 | 0 |
| 150,000– | 5% | 150,000 | 7,500 |
| 300,000– | 10% | 9,500 | 950 |
A 40,000 baht salary reaches the 10% bracket, but that does not mean all of it is taxed at 10%: each bracket only taxes the income inside it. The actual average rate is about 1.8% of annual income.
A 40,000 baht salary is only 9,500 baht into the 10% bracket
Net taxable income of 309,500 baht is just 9,500 baht above the 300,000 baht line where the rate goes from 5% to 10%. Only that part is taxed at 10%; the rest is still taxed at 5% or less. A raise that pushes you into a new bracket does not make your whole salary more expensive to tax.
What this means for planning: the first 9,500 baht of extra allowances saves the full 10%, but the next amount only saves 5%.
| Tax for the year, no extra allowances | 8,450 |
|---|---|
| Extra allowances of 9,500 baht (e.g. life insurance) | 7,500 (950 less) |
| Another 10,000 baht of allowances | 7,000 (500 less) |
If you are buying a fund or insurance purely to save tax, the first 9,500 baht is the part that pays off most; after that, every 10,000 baht saves 500 baht. Decide on your savings goals too, not tax alone.
Your employer already withholds tax. Why file?
Your employer withholds tax from each payslip based on an estimate of your annual income (the total is on your 50 Tawi certificate), but you still have to file a PND 91 return after the year ends. If you have allowances your employer did not count, such as life insurance, RMF or mortgage interest, your real tax is lower than what was withheld and you get the difference back. Enter the total from your 50 Tawi in "Tax withheld by employer" above to see your refund.
How much more can you save?
Every extra 10,000 baht of allowances cuts your tax by about 975 baht. Allowances you still have room for (figures for planning, not investment advice):
- RMF room for up to 144,000 baht more, cutting tax by up to 7,675 baht
- Thai ESG room for up to 144,000 baht more, cutting tax by up to 7,675 baht
- Life/health insurance room for up to 100,000 baht more, cutting tax by up to 5,475 baht
Bonus or side income too?
A bonus counts as 40(1) income, the same as salary. Freelance 40(2) income shares the 100,000 expense cap with your salary, so tax rises faster than many people expect. Enter your figures in the calculator above, or go to the 2026 Thai tax calculator.
Tax on other salaries
| Monthly salary (THB) | Annual income | Annual tax | Per month |
|---|---|---|---|
| 30,000 | 360,000 | 1,975 | 165 |
| 40,000 | 480,000 | 8,450 | 704 |
| 50,000 | 600,000 | 20,450 | 1,704 |
| 60,000 | 720,000 | 34,925 | 2,910 |
| 100,000 | 1,200,000 | 122,375 | 10,198 |
Based on 12 months of salary, the 100,000 expense deduction, the 60,000 personal allowance and social security. Bonuses and other allowances are not included.
Or enter your own salary in the calculator above.
Frequently asked questions
Do I need to file tax on a 40,000 baht salary?
Yes. Your annual salary of 480,000 baht is above the 120,000 baht filing threshold (single), so you must file a PND 91 return for 2026 income by 31 March 2027, even though your employer withholds tax every month.
What tax bracket is a 40,000 baht salary in?
With only the personal allowance and social security, your net taxable income is 309,500 baht, which reaches the 10% bracket. That does not mean all your salary is taxed at 10%: each bracket only taxes the part of income inside it. Your actual average rate is about 1.8% of annual income.
My employer already withholds tax every month. Will I get a refund?
You get a refund if your employer withheld more than the tax you actually owe, for example when you have allowances your employer does not know about (life insurance, RMF, Thai ESG, mortgage interest). Find the total withheld on your 50 Tawi certificate and enter it in the calculator above to see whether you pay more or get money back.
How much do I need to deduct on a 40,000 baht salary to stay in the 5% bracket?
9,500 baht more in allowances brings net taxable income down to exactly 300,000 baht, cutting the year's tax from 8,450 to 7,500 baht. Beyond that, every 10,000 baht saves 500 baht.
Sources
About this calculator
Made by WorkingBee using the same 2026 Thai tax rules as our LINE bot. Your numbers are calculated in your browser and are never sent to or stored on a server. Last updated · Figures are estimates for planning and may differ from what you finally file with the Revenue Department.