422 Tax
Today: 9 Nov 2026

Tax calculator

Three calculators in plain Java (TaxService) - change a number and press Calculate.

VAT - value added tax

Before VAT10,000.00 VAT700.00 Including VAT10,700.00

net = amount x 100 / (100 + rate)

Withholding tax on a payment

Base for withholding tax50,000.00 + VAT3,500.00 = Invoice total53,500.00 - Withholding tax 3%1,500.00 Transfer to the vendor52,000.00

Withholding tax is calculated on the amount before VAT. Gross-up: base = net / (1 - rate).

Personal income tax (salary)

Progressive Thai brackets on net income
Net income bracketRateTaxable in bracketTax
0 - 150,000 0% 150,000.00 0.00
150,000 - 300,000 5% 150,000.00 7,500.00
300,000 - 500,000 10% 200,000.00 20,000.00
500,000 - 750,000 15% 0.00 0.00
750,000 - 1,000,000 20% 0.00 0.00
1,000,000 - 2,000,000 25% 0.00 0.00
2,000,000 - 5,000,000 30% 0.00 0.00
5,000,000 and more 35% 0.00 0.00
Tax for the year27,500.00
Income720,000.00 - Expenses (50 %, max 100,000)100,000.00 - Allowances (60,000 personal + other)120,000.00 = Net income500,000.00 Tax for the year27,500.00 Withheld per month2,291.67 Effective rate3.8%
How this works - feature 422 VAT in / out, withholding tax with gross-up, personal income tax.

Concepts

  • VAT inclusive: net = gross x 100 / 107. Exclusive: VAT = net x 7 %.
  • Withholding tax is on the amount before VAT.
  • Gross-up: the payer bears the tax, base = net / (1 - rate).
  • Personal income tax: progressive brackets from 0 % to 35 % on net income.

Read the code

  • service/TaxService#vat
  • service/TaxService#wht
  • service/TaxService#personalIncomeTax