Overtime Pay Formula
Learn how overtime pay, total gross pay, and effective hourly earnings are calculated for a pay period.
The overtime pay formula estimates how much gross pay comes from regular hours and how much comes from overtime hours. Understanding the math helps you check payroll estimates, compare different overtime rates, and see how extra hours change your average hourly earnings.
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Total Gross Pay
Where:
Multiply your regular hourly rate by your regular hours, then multiply your hourly rate by the overtime multiplier and overtime hours. Add those two amounts to get total gross pay.
Variables Explained
| Variable | What It Means | Unit |
|---|---|---|
| hourlyRate - Hourly Rate | Your standard gross hourly wage before deductions. | currency |
| regularHours - Regular Hours Worked | Hours paid at the normal hourly rate during the pay period. | hours |
| overtimeHours - Overtime Hours Worked | Hours paid at the overtime rate during the same pay period. | hours |
| overtimeMultiplier - Overtime Rate Multiplier | The factor applied to the hourly rate for overtime, such as 1.5 or 2. | N/A |
| totalPay - Total Gross Pay | Combined regular pay and overtime pay before deductions. | currency |
| totalHours - Total Hours Worked | The sum of regular and overtime hours. | hours |
| effectiveHourlyRate - Effective Hourly Rate | Average gross earnings per hour across all hours worked. | currency |
Step-by-Step Calculation
Calculate regular pay
This gives the gross pay earned from non-overtime hours.
regularPay = hourlyRate * regularHours
Calculate the overtime hourly rate
This adjusts your normal rate using the overtime multiplier.
overtimeRate = hourlyRate * overtimeMultiplier
Calculate overtime pay
This gives the gross pay earned from overtime hours only.
overtimePay = overtimeRate * overtimeHours
Calculate total hours worked
This combines all hours worked in the pay period.
totalHours = regularHours + overtimeHours
Calculate total gross pay
This adds together regular pay and overtime pay.
totalPay = regularPay + overtimePay
Calculate effective hourly rate
This shows your average gross earnings per hour across all worked hours while avoiding division by zero.
effectiveHourlyRate = totalPay / max(totalHours, 1)
Example: Weekly overtime at time-and-a-half
Regular pay
20 × 40
$800.00
Overtime hourly rate
20 × 1.5
$30.00 per hour
Overtime pay
30 × 5
$150.00
Total gross pay
800 + 150
$950.00
Effective hourly rate
950 ÷ 45
$21.11 per hour
Final Result
Estimated overtime pay is $150.00 and total gross pay is $950.00 for the week.
Assumptions
- ✓A single overtime multiplier applies to all overtime hours entered.
- ✓The hourly rate stays the same for all regular hours in the selected pay period.
- ✓Results are gross pay estimates before tax, retirement contributions, insurance, and other deductions.
- ✓Regular and overtime hours are assumed to belong to the same pay period.
Limitations
- !The formula does not handle multiple overtime bands, such as some hours at 1.5x and others at 2x, in one calculation.
- !The calculator does not determine whether hours legally qualify as overtime in your location or contract.
- !It does not include bonuses, shift differentials, holiday premiums, unpaid breaks, or minimum-hour guarantees.
- !Payroll systems may round hours or pay differently, so actual payslips can vary slightly.
Common Mistakes to Avoid
Entering total hours as regular hours and then also entering overtime hours, which double-counts some time.
Using net hourly pay instead of gross hourly pay before deductions.
Forgetting to change the multiplier when overtime is paid at double time instead of time-and-a-half.
Mixing hours from different pay periods in one estimate.
Assuming the calculator includes taxes, pension contributions, or other payroll deductions automatically.
Related Formulas
Frequently Asked Questions
How do you calculate overtime pay manually?
First multiply the hourly rate by the overtime multiplier to get the overtime rate. Then multiply that overtime rate by overtime hours. Add the result to regular pay if you want total gross pay.
What is the formula for time-and-a-half pay?
Time-and-a-half pay is calculated as hourlyRate × 1.5. Overtime pay then becomes hourlyRate × 1.5 × overtimeHours.
What is the formula for double-time pay?
Double-time pay uses hourlyRate × 2 for the overtime rate. Total overtime pay is then hourlyRate × 2 × overtimeHours.
Why is effective hourly rate higher than the normal hourly rate?
It increases when some of your hours are paid at a multiplier above 1.0, because your total gross pay is spread across all hours worked.
Does the formula include taxes or payroll deductions?
No. The formula estimates gross pay only, before any deductions are taken out.
Can I use the formula for monthly or biweekly pay?
Yes, as long as the regular hours and overtime hours you enter match that same pay period.
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