How to Calculate Work Hours (With Breaks & Overtime)
Learning how to calculate work hours correctly helps employees, freelancers, managers, and business owners track time accurately, avoid payroll mistakes, and estimate overtime more easily.
Whether you are filling out a timesheet, reviewing payroll hours, calculating shift length, or converting worked time into decimal hours, understanding the correct process is important.
This guide explains exactly how to calculate hours worked step by step, including unpaid lunch breaks, overtime hours, overnight shifts, and weekly totals.
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Use the Work Hours CalculatorWho This Guide Is For
- Hourly employees tracking shifts
- Freelancers calculating billable hours
- Managers reviewing employee timesheets
- Payroll staff calculating worked time
- Remote workers tracking schedules
- Contractors estimating weekly earnings
What Are Work Hours?
Work hours are the total number of hours spent working during a day or week after unpaid break deductions are removed.
For most employees, work hours begin when they clock in and end when they clock out. Unpaid lunch breaks are usually excluded from total worked time.
This basic formula works for:
- Daily work shifts
- Weekly timesheets
- Payroll calculations
- Overtime calculations
- Freelance billable hours
How to Calculate Work Hours Step by Step
1. Record Your Start Time
Write down the exact time you started working.
Example: 8:30 AM
2. Record Your End Time
Write down the time your shift ended.
Example: 4:45 PM
3. Calculate Total Time Between Hours
From 8:30 AM to 4:45 PM equals:
8 hours and 15 minutes
4. Subtract Unpaid Breaks
If you took a 30-minute unpaid lunch break:
8 hours 15 minutes − 30 minutes = 7 hours 45 minutes worked
5. Convert Minutes Into Decimal Hours
Many payroll systems use decimal hours instead of standard hours and minutes.
To convert minutes into decimal hours:
Minutes ÷ 60 = Decimal Hours
Minutes to Decimal Hours Conversion Chart
| Minutes | Decimal Hours |
|---|---|
| 5 | 0.08 |
| 10 | 0.17 |
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 45 | 0.75 |
| 50 | 0.83 |
Example of Calculating Daily Work Hours
- Start time: 9:00 AM
- End time: 5:30 PM
- Lunch break: 1 hour unpaid
Total time between 9:00 AM and 5:30 PM: 8 hours 30 minutes
After subtracting the lunch break: 7 hours 30 minutes worked
Decimal format: 7.5 hours
How to Calculate Weekly Work Hours
To calculate weekly work hours, add together the total worked hours for each day of the week.
Tuesday: 7.5 hours
Wednesday: 8 hours
Thursday: 8.5 hours
Friday: 7 hours
Total Weekly Hours = 39 Hours
If you work more than your overtime threshold, additional hours may qualify as overtime pay.
You can estimate overtime earnings using our Overtime Pay Calculator.
How to Calculate Overnight Shift Hours
Overnight shifts pass midnight, which can make calculations more confusing manually.
- Start: 10:00 PM
- End: 6:00 AM
- Break: 30 minutes unpaid
10:00 PM → Midnight = 2 hours
Midnight → 6:00 AM = 6 hours
Total = 8 hours
Minus break = 7.5 hours worked
If you regularly work overnight shifts, a Time Duration Calculator can simplify time tracking significantly.
Common Work Hour Calculation Mistakes
- Forgetting to subtract unpaid breaks
- Mixing up AM and PM times
- Incorrect decimal conversions
- Calculation errors with overnight shifts
- Adding weekly totals incorrectly
- Forgetting overtime thresholds
Why Accurate Work Hour Tracking Matters
Accurate work hour calculations help:
- Ensure correct employee pay
- Reduce payroll disputes
- Improve timesheet accuracy
- Track productivity more effectively
- Estimate overtime earnings correctly
- Improve freelance invoicing accuracy
Frequently Asked Questions
How do I calculate work hours manually?
Subtract your start time from your end time, then subtract unpaid breaks from the total.
How do I calculate overtime hours?
Add your total weekly hours and compare them to your overtime threshold, such as 40 hours per week.
How do I convert minutes into decimal hours?
Divide the number of minutes by 60. Example: 30 minutes ÷ 60 = 0.50 hours.
How do overnight shifts work?
If your shift passes midnight, calculate the hours before midnight separately from the hours after midnight.
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Use our free calculator to calculate shifts, break deductions, overtime, and weekly work hours automatically.
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