About the Hours Calculator
An hours calculator works out the time elapsed between a start and an end time, returning both hours and minutes and the decimal hours figure payroll systems need. It is the calculation behind every timesheet.
The formula
Hours = (end − start) in minutes / 60Times are converted to minutes past midnight, subtracted, and divided by 60. Decimal hours express minutes as a fraction: 30 minutes is 0.5 hours.
How to use this calculator
- 1Enter your Start Hour (0–23). The field starts at
9, which you can overwrite. - 2Enter your Start Minute (0–59). The field starts at
0, which you can overwrite. - 3Enter your End Hour (0–23). The field starts at
17, which you can overwrite. - 4Enter your End Minute (0–59). The field starts at
30, which you can overwrite. - 5Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Start Hour (0–23) | 9 |
| Start Minute (0–59) | 0 |
| End Hour (0–23) | 17 |
| End Minute (0–59) | 30 |
Result
Duration: 8h 30m
Decimal Hours: 8.50 hrs
Weekly Total (5 days): 42.50 hrs
Minutes: 510 min
Seconds: 30600 sec
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
The distinction between decimal hours and hours-and-minutes causes real payroll errors. Seven hours and 30 minutes is 7.5 decimal hours, not 7.30. Reading a timesheet entry of 7.30 as seven and a half hours, or entering 7.5 where 7 hours 50 minutes was meant, produces discrepancies that compound across a pay period.
Shifts crossing midnight need care, because the end time is numerically lower than the start. A shift from 22:00 to 06:00 is eight hours, not negative sixteen, so the calculation has to add 24 hours when the end precedes the start.
Things worth knowing
- Decimal hours: 15 minutes is 0.25, 30 is 0.5, 45 is 0.75. These are the four values worth memorising.
- Deduct unpaid breaks explicitly. Most jurisdictions do not count meal breaks as worked time.
- For shifts crossing midnight, add 24 hours to the end time before subtracting.
- Overtime rules vary — US federal law uses over 40 hours per week, while many other countries use daily thresholds.
- Round consistently. Some employers round to the nearest quarter hour, which must be applied evenly to be lawful.
Frequently asked questions
How do I calculate hours worked?+
Subtract the start time from the end time and deduct any unpaid breaks. From 9:00 to 17:30 with a 30-minute unpaid lunch is 8 hours.
What are decimal hours?+
Hours with minutes expressed as a fraction. 7 hours 30 minutes is 7.5 decimal hours. Payroll systems use this format, and confusing 7.30 with 7.5 is a common source of error.
How do I handle a shift that crosses midnight?+
Add 24 hours to the end time before subtracting. A 22:00 to 06:00 shift is 8 hours, which the calculation must recognise rather than returning a negative result.
Do breaks count as worked hours?+
Unpaid meal breaks generally do not, while short paid rest breaks generally do. Rules vary by jurisdiction and by employment contract, so check the applicable law.