How to Calculate Overtime (OT): Monthly, Daily and Holiday Pay
Overtime pay is calculated as hourly wage × the legally required rate × hours worked. For monthly employees, the hourly wage is calculated as (monthly salary ÷ 30 ÷ normal working hours per day). For daily employees, it is (daily wage ÷ normal working hours per day). Under the Labour Protection Act B.E. 2541 (1998), the minimum rates fall into three categories: 1.5 times for overtime on normal working days, 1 or 2 times for work during normal hours on holidays, and 3 times for overtime beyond normal hours on holidays.
What Overtime Rates Apply Under Thai Labour Law?
The minimum rate is 1.5 times the hourly wage for overtime on normal working days, 1 time for holiday work by employees entitled to holiday pay, or 2 times for employees not entitled to holiday pay. Holiday overtime must be paid at least 3 times the hourly wage. These are minimum rates; companies may offer higher rates.
| Type of Work | Minimum Rate | Applies To | Labour Protection Act Reference |
|---|---|---|---|
| Overtime on normal working days | 1.5 times | All employee types | Section 61 |
| Holiday work during normal working hours | 1 time (in addition to holiday pay) | Employees entitled to holiday pay, such as monthly employees | Section 62 (1) |
| Holiday work during normal working hours | 2 times | Employees not entitled to holiday pay, such as daily employees on weekly rest days | Section 62 (2) |
| Overtime on holidays | 3 times | All employee types | Section 63 |
For a detailed explanation of overtime pay and holiday work pay, see
Overtime Calculation Methods
Employees who work overtime on normal working days receive overtime pay at a rate of at least 1.5 times their hourly wage. For overtime on holidays, including weekends, public holidays and customary holidays, employees receive at least 3 times their hourly wage. The calculation methods for each employee type are as follows:
How to Calculate OT for Monthly Employees
- Formula: (Monthly salary / 30 / Normal daily working hours) X (1.5 or 3) X (Overtime hours)
- Example: Overtime at 1.5 times the hourly wage for 4 hours
- OT pay for that day = (15,000 / 30 / 8) X 1.5 X 4 = THB 375
How to Calculate OT for Daily Employees
- Formula: (Daily wage / Normal daily working hours) X (1.5 or 3) X (Overtime hours)
- Example: Overtime at 3 times the hourly wage for 3 hours
- OT pay for that day = (400 / 8) X 3 X 3 = THB 450
Calculating Holiday Pay
Holiday work pay and overtime pay are calculated as follows:
Employees Entitled to Holiday Pay
- Employees entitled to holiday pay, such as monthly employees, receive additional holiday work pay of at least 1 time their hourly wage.
- Formula: (Monthly salary / 30 / Normal daily working hours) X 1 X (Hours worked)
- Example: (15,000 / 30 / 8) X 1 X 8
- Pay for work on that holiday = THB 500
Employees Not Entitled to Holiday Pay
- Employees not entitled to holiday pay, such as daily employees, receive holiday work pay of at least 2 times their hourly wage.
- Formula: (Daily wage / Normal daily working hours) X 2 X (Hours worked)
- Example: (350 / 8) X 2 X 8
- Pay for work on that holiday = THB 700
Summary: How to Calculate Every Type of OT
Calculate pay in two steps: determine the hourly wage, then multiply it by the applicable rate (1.5 / 1 / 2 / 3) and the hours worked. Common HR mistakes include applying the wrong holiday rate to an employee type and failing to distinguish holiday work during normal hours from holiday overtime.
If your organisation employs both monthly and daily employees, manual calculations each pay period increase the risk of errors. calculates OT at every rate using data from the , then includes the amounts in payroll together with tax and social security calculations.
FAQ: Frequently Asked Questions About OT Calculation
Q: What is the overtime rate on a normal working day?
A: At least 1.5 times the hourly wage for each hour worked beyond normal working hours. This applies to both monthly and daily employees.
Q: Is holiday work paid at 2 or 3 times the hourly wage?
A: It depends on whether the work falls within or beyond normal working hours. During normal hours on holidays, monthly employees receive an additional 1 time their hourly wage, while daily employees receive 2 times. For work beyond normal hours on holidays, all employees receive 3 times the hourly wage.
Q: Why is a monthly salary divided by 30?
A: Labour protection law requires the daily wage of a monthly employee to be calculated by dividing the monthly salary by 30. This is then divided by normal daily working hours to obtain the hourly wage, regardless of whether the month has 28 or 31 days.
Q: With a monthly salary of THB 15,000, how much is 1 hour of OT?
A: With a normal 8-hour working day, the hourly wage is THB 62.50. One hour of OT on a normal working day earns THB 93.75, while one hour of holiday OT earns THB 187.50.
Q: Can an employer require employees to work OT?
A: Generally, no. The employee must consent beforehand, except for continuous work where stopping would cause damage, or emergency work.
Q: What is the maximum number of OT hours per week?
Overtime on working days, holiday work and holiday overtime must not exceed a combined total of 36 hours per week under the ministerial regulation issued pursuant to the Labour Protection Act.
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