Incomplete Month Salary Calculator (2026)

When you work an incomplete month (e.g. joining or leaving mid-month), your salary is pro-rated based on the number of calendar or working days. The most common formula is: Monthly Salary / Total Working Days in Month x Number of Days Worked. Some employers use calendar days instead of working days.

The standard formula is: Pro-rated Salary = Monthly Salary / Total Working Days in the Month x Actual Days Worked. For example, if your monthly salary is $5,000, there are 22 working days, and you worked 10 days, your pro-rated salary is $5,000 / 22 x 10 = $2,272.73.

Incomplete month salary applies when you start a new job mid-month, resign or are terminated before month-end, take unpaid leave for part of the month, or transition between contracts within the same month. Your employment contract should specify the pro-rating method used.

Yes. CPF contributions are calculated based on your actual wages for the month, including pro-rated salary. Both employee and employer CPF contributions are computed on the pro-rated amount, subject to the ordinary wage ceiling of $8,000 per month.

Under the MOM working-days method, a public holiday that falls on a normal working day is generally counted as a working day in the denominator if the employee would normally have been entitled to be paid for it. In practice, this means a month with more public holidays has a smaller working-days denominator, which produces a slightly higher daily rate and a slightly higher pro-rated amount for partial-month employees. The calendar-days method ignores public holidays altogether — every day in the month counts equally. Employers should apply the same method consistently across all pay cycles. If your employer changes methods unilaterally, that is generally a contract variation requiring your agreement.

New hires starting mid-month are paid for the days from their start date to the end of the month, pro-rated using whichever method is specified in the employment contract or staff handbook. Under the MOM working-days method, the calculation is: full monthly salary ÷ working days in the month × working days from start date to month-end. CPF is deducted on the pro-rated wage, not on the full month. The employer must also pro-rate employer CPF, annual leave entitlement (typically based on completed months of service), and any monthly allowances. Probation periods are unaffected by the pro-ration — they start running from the first day of work regardless of whether it is a full or partial month.

Part-time workers in Singapore are typically paid by the hour or by the day rather than as a monthly salary, so the standard incomplete-month formula does not apply directly. Their pay is simply hours worked × hourly rate (or days worked × daily rate). However, if a part-time worker is on a monthly retainer with set days of work per week, and they join or leave mid-month, the pro-rating formula still applies — divide the monthly retainer by the contracted working days in the month and multiply by days actually worked. The Employment Act (Part-Time Employment) Regulations require part-time workers to receive pro-rated benefits including paid leave, sick leave and public holiday pay relative to a full-time equivalent.

The Ministry of Manpower's default guidance is the working-days method: monthly gross rate of pay ÷ total number of working days in the month × number of days the employee actually worked in that month. Working days exclude weekly rest days. This is the method MOM uses in its own Employment Act guidance and in its salary calculation examples. Employers are not strictly required to use the working-days method — the calendar-days method is also accepted in practice — but the method used must be stated in the employment contract or company policy, and it must be applied consistently. If your contract is silent, the working-days method is the safest default to assume.