Prorated Salary Calculator
Calculate how much should be paid when someone works only part of a pay period.
What Is a Prorated Salary?
A prorated salary is a partial salary payment based on the portion of time an employee actually worked during a pay period. This usually applies when someone starts mid-period, leaves before period end, or changes status during payroll.
When You Need a Prorated Salary Calculation
- New hire starts after the beginning of a payroll cycle
- Employee resigns or is terminated before the cycle ends
- Unpaid leave reduces payable days in a period
- Contractor or fixed-term staff work only part of a month
Core Formula
Most payroll teams follow this structure:
Prorated Pay = (Full Period Salary) × (Worked Days ÷ Total Days in Period)
The calculator above determines your full period salary from annual salary and pay frequency, then applies the day ratio. You can choose to use either calendar days or weekdays only, depending on your policy.
How This Calculator Works
1) Finds the full pay period amount
Annual salary is divided by number of pay periods per year:
- Weekly: 52
- Biweekly: 26
- Semi-monthly: 24
- Monthly: 12
2) Measures total eligible days in the period
Depending on your selected proration method, the calculator counts either all calendar days or weekdays only.
3) Measures worked days in the same period
It uses the employee start/end dates and trims them to the selected pay period.
4) Applies the ratio
Worked days divided by total days gives the payable percentage. That percentage is applied to the full period salary.
Example Scenario
Suppose annual salary is $78,000 on a semi-monthly payroll (24 periods), and an employee starts halfway through a period. If there are 10 weekdays in the period and they worked 5 weekdays:
- Full semi-monthly pay = 78,000 ÷ 24 = 3,250
- Worked fraction = 5 ÷ 10 = 50%
- Prorated pay = 3,250 × 0.50 = 1,625
Calendar Days vs. Weekdays
There is no single universal rule. Companies use different payroll policies:
- Calendar day method: simple and common in monthly payroll environments
- Weekday method: useful when compensation is tied to business days worked
Always align with your HR and payroll policy, employment contract, and local regulations.
Common Mistakes to Avoid
- Using the wrong pay frequency divisor
- Mixing calendar and business-day methods
- Forgetting inclusive date counting (start and end days)
- Not documenting the chosen proration policy
Quick FAQ
Does this include taxes or deductions?
No. This calculator returns gross prorated salary only. Taxes, benefits, retirement, and other deductions are separate.
Can I use this for hourly employees?
Hourly payroll is usually based directly on hours worked. This tool is designed primarily for salaried proration.
Should I round before or after proration?
Most systems calculate with full precision and round the final gross amount to two decimals. Follow your payroll system rules.
Final Notes
A clear proration method improves payroll accuracy and avoids disputes. Use this calculator for fast estimates, then apply your company’s official payroll procedures for final processing.