How to Calculate Overtime Pay in Thailand: Complete Guide 2025

Overview of Overtime Pay in Thailand

Thailand’s Labour Protection Act B.E. 2541 (1998) establishes clear rules for overtime compensation. Whether you’re an employee checking your pay slip or an employer ensuring compliance, understanding these rates is essential.

The law mandates premium pay rates for work performed beyond normal working hours, on holidays, and for overtime on holidays. Each scenario has a different multiplier.

Use our Calculate your OT pay tool for an instant breakdown of your overtime earnings.

Step 1: Calculate Your Hourly Rate

Before calculating overtime, you need to determine your base hourly rate. The formula differs slightly based on your pay structure:

For Monthly-Salaried Employees

Hourly rate = Monthly salary ÷ 30 ÷ 8

The law uses 30 days per month (regardless of actual calendar days) and 8 hours per day as the standard.

Example: Monthly salary of 20,000 THB

• Daily rate: 20,000 ÷ 30 = 666.67 THB
• Hourly rate: 666.67 ÷ 8 = 83.33 THB/hour

For Daily-Wage Employees

Hourly rate = Daily wage ÷ 8

Example: Daily wage of 400 THB

• Hourly rate: 400 ÷ 8 = 50 THB/hour

Overtime Rate Categories

Thailand’s law defines four distinct overtime scenarios, each with its own multiplier:

1. Weekday Overtime (1.5× Rate)

When you work beyond the normal 8 hours on a regular working day, you receive 1.5 times your hourly rate for each overtime hour.

Weekday OT pay = Hourly rate × 1.5 × OT hours

Example: Hourly rate 83.33 THB, worked 3 hours OT on a weekday

• OT pay: 83.33 × 1.5 × 3 = 375 THB

2. Holiday Work — First 8 Hours

The rate for working on a holiday (during regular hours) depends on your employment type:

Employee Type	Rate	Reason
Monthly-salaried	1× hourly rate	Already paid for holidays in monthly salary
Daily-wage	2× hourly rate	Not normally paid for holidays

Example (monthly employee): Hourly rate 83.33 THB, worked 8 hours on a holiday

• Holiday pay: 83.33 × 1 × 8 = 666.67 THB (extra, on top of monthly salary)

Example (daily employee): Hourly rate 50 THB, worked 8 hours on a holiday

• Holiday pay: 50 × 2 × 8 = 800 THB

3. Holiday Overtime — Beyond 8 Hours (3× Rate)

When you work more than 8 hours on a holiday, the hours exceeding 8 are compensated at 3 times your hourly rate. This is the highest OT rate under Thai law.

Holiday OT pay = Hourly rate × 3 × hours beyond 8

Example: Hourly rate 83.33 THB, worked 11 hours on a holiday

• First 8 hours (monthly employee): 83.33 × 1 × 8 = 666.67 THB
• Extra 3 hours: 83.33 × 3 × 3 = 750 THB
• Total holiday compensation: 1,416.67 THB

Complete Rate Summary Table

Scenario	Multiplier	Monthly Employee	Daily Employee
Weekday OT	1.5×	1.5× hourly	1.5× hourly
Holiday work (first 8 hrs)	1× / 2×	1× hourly	2× hourly
Holiday OT (beyond 8 hrs)	3×	3× hourly	3× hourly

Practical Example: Full Month Calculation

Let’s calculate a complete month’s OT for an employee earning 20,000 THB/month:

Work performed this month:

• Weekday overtime: 20 hours
• Worked 1 holiday (full day, 8 hours)
• Holiday overtime: 2 hours (beyond the 8-hour holiday)

Step-by-step calculation:

1. Hourly rate: 20,000 ÷ 30 ÷ 8 = 83.33 THB

2. Weekday OT: 83.33 × 1.5 × 20 = 2,500 THB

3. Holiday work (8 hrs, monthly employee): 83.33 × 1 × 8 = 666.67 THB

4. Holiday OT (2 hrs): 83.33 × 3 × 2 = 500 THB

Total OT compensation: 2,500 + 666.67 + 500 = 3,666.67 THB

Total monthly pay: 20,000 + 3,666.67 = 23,666.67 THB (before deductions)

To see your take-home pay after tax and Social Security deductions, use our Net Salary Calculator.

Legal Limits on Overtime (Section 26)

Thai law sets clear boundaries on how much overtime an employer can require:

Maximum Weekly OT: 36 Hours

• Total overtime hours must not exceed 36 hours per week
• This includes weekday OT and holiday OT combined
• Employers who exceed this limit are violating the law

Employee’s Right to Refuse

• Employees can refuse overtime work in most cases
• Employers cannot punish or terminate employees for refusing OT
• Exception: Work that is continuous in nature and would be damaged if stopped

Exceptions to the 36-Hour Limit

Certain industries have different rules:

• Hotels, restaurants, and entertainment venues
• Transport services
• Work that must be performed continuously (stopping would cause damage)
• Emergency situations (temporary only)

What Counts as “Wages” for OT Calculation?

The base for OT calculation includes:

• Basic monthly salary
• Fixed position allowances paid regularly
• Any regular fixed compensation

It does not include:

• Commissions
• Bonuses
• Transportation allowances
• Housing allowances
• Expense reimbursements
• Variable performance pay

OT Pay and Taxes

Overtime pay is considered assessable income and is subject to:

• Personal income tax — added to your total annual income
• Social Security contributions — calculated on total compensation up to the 15,000 THB monthly cap
• Withholding tax — your employer should withhold the appropriate amount

Common Issues and How to Address Them

Unpaid Overtime

If your employer isn’t paying the correct OT rates:

1. Document your actual working hours (keep personal records)
2. Compare with your pay slip calculations
3. Raise the issue with HR in writing
4. If unresolved, file a complaint with the Labour Inspector

”All-Inclusive” Salary

Some employers claim the salary already includes OT. Under Thai law, this arrangement must be clearly specified in the employment contract, and the hourly rate calculation must still meet minimum wage requirements for all hours worked.

Forced Unpaid Overtime

Requiring employees to work overtime without compensation is illegal. Common violations include:

• “Voluntary” extra hours that are actually expected
• Requiring pre-shift preparation or post-shift cleanup without pay
• Working through lunch breaks without compensation

Minimum Wage Considerations

When calculating OT for minimum-wage workers, remember:

• The 2025 minimum wage varies by province (337-400 THB/day depending on area)
• OT rates are calculated on actual wages, which must meet or exceed minimum wage
• Even with OT, the hourly rate for any hour worked must not fall below minimum wage equivalents

Frequently Asked Questions

Is OT mandatory for employees in Thailand?

No. Under the Labour Protection Act, overtime work requires the employee’s consent except in specific circumstances (emergency work, continuous operations that would be damaged if stopped, or certain industries like hospitality). An employer cannot force overtime or punish employees for refusing.

How do I calculate OT if I work rotating shifts?

For shift workers, the same rules apply. Your “normal working hours” are whatever your shift schedule defines (maximum 8 hours/day or 48 hours/week). Any hours beyond your scheduled shift are overtime and must be paid at the applicable premium rate.

Does working from home count for OT purposes?

Yes. If you perform work outside your normal hours — regardless of location — you’re entitled to overtime pay. The key factors are: the work was assigned or authorized by the employer, it was performed beyond normal working hours, and you can demonstrate the time spent. Keep records of communications and work performed during overtime hours.