Hours calculator: time worked between two clock times
Enter a start time, an end time and any unpaid break. 9:00 AM to 5:30 PM with a 30-minute unpaid lunch is 8 hours. If the end time is earlier than the start, the shift is treated as running past midnight.
Inputs used by this calculator
Hours Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Start time | 09:00 | Text in the format shown | Supplies the start time quantity used by the published equation or result breakdown. |
| End time | 17:30 | Text in the format shown | Supplies the end time quantity used by the published equation or result breakdown. |
| Unpaid break (minutes) | 30 | 0 to 1440 | Supplies the unpaid break (minutes) quantity used by the published equation or result breakdown. |
How hours between two times are counted
The calculator converts both times to minutes after midnight, subtracts the start from the end and removes the unpaid break. The answer is shown in decimal hours for timesheets and payroll, and in hours and minutes.
worked = end − start − unpaid breakdecimal hours = minutes ÷ 60Overnight shifts
When the end time is earlier than the start, such as 10:00 PM to 6:00 AM, the calculator adds 24 hours to the end time, giving an 8-hour shift. For shifts longer than 24 hours or spanning several days, use the Time Card Calculator.
Which breaks to subtract
Under the federal Fair Labor Standards Act, the Department of Labor explains that short rest breaks, usually 20 minutes or less, are customarily paid as working time, while bona fide meal periods, typically 30 minutes or more, generally need not be paid if the employee is fully relieved from duty. Subtract only the unpaid time; state laws and employer policies can add rules.
Converting minutes to decimal hours
Payroll systems often want hours as a decimal: 8 hours 45 minutes is 8.75 hours, because 45 ÷ 60 = 0.75. The table below lists common minute values. Multiplying decimal hours by the hourly rate gives gross pay before deductions.
Overtime
For covered, non-exempt employees, federal law requires overtime at one and one-half times the regular rate for hours over 40 in a workweek. Overtime is counted per week, not per day, under federal rules, although some states count daily overtime. Add daily hours for the week before applying the 40-hour threshold.
Checking a timesheet
Round the same way your employer does, keep start and end times in the same format, and record breaks separately. If a shift crosses a daylight saving time change, the clock gains or loses an hour; count the actual time worked.
Minutes as decimal hours
| Minutes | Decimal hours | Share of an hour |
|---|---|---|
| 5 min | 0.08 | 8% of an hour |
| 10 min | 0.17 | 17% of an hour |
| 15 min | 0.25 | 25% of an hour |
| 20 min | 0.33 | 33% of an hour |
| 25 min | 0.42 | 42% of an hour |
| 30 min | 0.5 | 50% of an hour |
| 35 min | 0.58 | 58% of an hour |
| 40 min | 0.67 | 67% of an hour |
| 45 min | 0.75 | 75% of an hour |
| 50 min | 0.83 | 83% of an hour |
| 55 min | 0.92 | 92% of an hour |
| 60 min | 1.0 | 100% of an hour |
Frequently asked questions
How do I calculate hours worked?
Subtract the start time from the end time and take out unpaid breaks.
How many hours is 9 to 5:30 with a 30-minute lunch?
8 hours.
How do I convert 45 minutes to decimal hours?
Divide by 60: 45 minutes is 0.75 hours.
Are breaks paid?
Under federal rules, short breaks of about 20 minutes or less are usually paid; bona fide meal periods of 30 minutes or more usually are not.
How are overnight shifts calculated?
If the end time is earlier than the start, the shift is treated as crossing midnight.
When does overtime start?
Under federal law, after 40 hours in a workweek for non-exempt employees, at 1.5 times the regular rate.
Can I add up a whole week?
Yes, with the Time Card Calculator, which handles several shifts and overtime.
What to keep in mind
If the end time is earlier, the shift is treated as crossing midnight.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.