In Indonesia, salary proration applies when an employee does not work a full calendar month — for example, when joining or leaving mid-month. The method used depends on whether the component is base salary or an allowance.
Base Salary — Calendar Day Method
Base salary is prorated using calendar days:
Formula: (Days Worked ÷ Total Calendar Days in Month) × Monthly Salary
Example: An employee with a monthly salary of IDR 20,000,000 joins on 5 January. January has 31 calendar days, so the employee works 27 of them (31 − 5 + 1):
(27 ÷ 31) × 20,000,000 = IDR 17,419,355
Allowances — Working Day Method
Allowances such as transport or work-from-home allowances are typically prorated by working days rather than calendar days.
Formula: (Working Days Worked ÷ Total Working Days in Month) × Allowance Amount
The total working days for the month will vary depending on the official public holiday calendar for that year. Check the monthly calendar when calculating.
Key Points
Base salary is always prorated by calendar days — not working days.
Allowances are typically prorated by working days.
Proration applies both to new starters and employees who leave before the month end.
The payslip will show the prorated amounts for each component separately.