Calculate shifts, breaks and weekly work hours in seconds.
Calculate Work Hours Quickly and Accurately
SumHours provides free work time calculators for employees, freelancers, contractors and anyone who needs to calculate hours worked. Enter your start and end times, subtract unpaid breaks and see your total in hours and minutes as well as decimal hours.
You can use SumHours for a single shift, multiple clock-in and clock-out periods, overnight work, weekly hours, timesheets and custom pay periods. For more detailed work schedules, the Work Hours Calculator includes weekly, timesheet and roster tools with printable results and CSV export.
Choose the Right Work Hours Calculator
Hours Calculator
Use the Hours Calculator when you need to calculate the time between two times. It is useful for one shift, multiple work periods and unpaid break deductions.
Work Hours & Timesheet
Use the Work Hours Calculator when you need daily totals, weekly work hours, a one- or two-week timesheet, a custom pay period, overtime calculations, printable time records or CSV export.
Clock In Calculator
The Clock In Calculator totals multiple clock-in and clock-out punches. It can also show how much work time remains, estimate when you can leave and calculate when to return from a lunch break.
Shift Calculator
The Shift Calculator calculates the length of a shift and handles work that continues past midnight. You can also calculate what time to clock out or what time to start when you know the required work duration and break.
Time to Decimal Calculator
Use the Time to Decimal Calculator to convert hours and minutes into decimal hours or convert decimal hours back into hours and minutes.
Overtime and Salary Calculators
The Overtime Calculator works out overtime pay at time and a half, double time or a custom rate. The Salary Calculator turns your hours, hourly rate and overtime into estimated gross pay.
Free Timesheet Templates
Prefer paper or Excel? Download a free weekly or biweekly timesheet template to print, or an Excel version that totals your hours and overtime for you. Planning around days off? See the public holidays for 2026 and 2027 in the US, Canada and the UK.
Common Work Hours Examples
Work-time calculations can look simple, but unpaid breaks, overnight shifts and decimal hours often cause mistakes. Here are a few common examples.
| Example | Result |
|---|---|
| 8:00 AM to 4:30 PM with a 30-minute unpaid break | 8 hours worked |
| 9:00 AM to 5:00 PM | 8 hours |
| 10:00 PM to 6:00 AM | 8 hours overnight |
| 8 hours 30 minutes | 8.50 decimal hours |
| 7 hours 45 minutes | 7.75 decimal hours |
Work Hours, Timesheets and Time Cards
A simple hours calculator is useful for one shift, while a timesheet is better when you need to record several days of work. SumHours lets you calculate individual work periods and then use the Work Hours & Timesheet tool for complete weekly or custom pay-period totals.
The timesheet can include multiple work periods per day, overnight work, unpaid breaks, daily totals, weekly totals, decimal hours and optional custom overtime rules. You can also print your timesheet, save it as a PDF or download the data as CSV.
Overtime settings are user-defined because overtime rules can vary by employer and jurisdiction. SumHours does not automatically assume that a particular overtime threshold applies to you.
Hours and Minutes vs Decimal Hours
Hours and minutes are not written the same way as decimal hours. For example, 8 hours 30 minutes is 8.5 hours, not 8.30 hours.
Because an hour contains 60 minutes, minutes are converted by dividing them by 60:
30 ÷ 60 = 0.50
So:
- 15 minutes = 0.25 hours
- 30 minutes = 0.50 hours
- 45 minutes = 0.75 hours
For any other value, use the Time to Decimal Calculator.
Calculate Overnight Work Hours
SumHours can calculate shifts that pass midnight. If your shift starts at 10:00 PM and ends at 6:00 AM, the elapsed time is 8 hours.
For clock-time calculations without separate dates, SumHours can treat an end time earlier than the start time as occurring on the following day where that behavior is appropriate for the selected calculator.
Why Use SumHours?
- No account required for normal calculations.
- Fast time entry with common 12-hour and 24-hour formats.
- Overnight shift support for work that continues past midnight.
- Decimal hour conversion for timesheets and payroll preparation.
- Weekly and custom timesheets for longer work periods.
- Print and CSV export on supported timesheet workflows.
- User-defined overtime instead of assuming one legal rule for everyone.
- Browser-local calculator data where the tool stores saved entries locally.
How SumHours Calculates Time
SumHours calculates work durations using minutes internally and then converts the result into hours, minutes and decimal hours for display. This helps avoid common mistakes such as treating 30 minutes as 0.30 of an hour.
Our calculator logic is tested against examples including normal workdays, midnight crossings, multiple work periods, break deductions and time conversions. You can read more on the Calculation Methodology page.
Frequently Asked Questions
How do I calculate the hours I worked?
Subtract your start time from your end time and then subtract any unpaid break. For example, 8:00 AM to 4:30 PM is 8 hours 30 minutes elapsed. After a 30-minute unpaid lunch, the worked total is 8 hours.
How do I calculate work hours with a lunch break?
Calculate the elapsed time between your start and end times, then subtract the unpaid lunch duration. If you clock out and back in for lunch, you can also enter the separate work periods instead.
How do I calculate weekly work hours?
Add the worked time for each day in the week. The Work Hours Calculator does this automatically and shows daily, weekly and pay-period totals.
How do I calculate a night shift that crosses midnight?
When an end time is earlier than the start time, it may represent the following day. For example, 10:00 PM to 6:00 AM is an 8-hour overnight period.
What is 8 hours 30 minutes in decimal hours?
Thirty minutes is half of an hour, so 8 hours 30 minutes equals 8.50 decimal hours.
Can I create a printable timesheet?
Yes. The Work Hours & Timesheet tool can create a printable work record and lets you use your browser’s Save as PDF option. CSV export is also available.