To find the time between two clock times, subtract the start from the end; if the end is earlier (an overnight shift), add 24 hours. Then subtract any unpaid break. 8:45 a.m. to 5:15 p.m. with a 30-minute lunch is 8 hours 0 minutes (8.00 decimal hours). Payroll systems usually want decimal hours: divide the minutes by 60, so 7 h 45 min = 7.75 hours.
Add an hourly rate to see the gross pay for the shift. This is a simple single-shift calculator; it doesn't apply overtime rules.
How to use the time duration calculator (hours between two times)
- Enter the start and end times (your device shows a 12- or 24-hour picker).
- Enter any unpaid break in minutes.
- Optionally enter an hourly rate.
- Read the time worked, decimal hours and pay. Repeat for each day and add up the decimal hours for a week.
Formula
Worked example
Shift from 8:45 a.m. to 5:15 p.m. with a 30-minute lunch, paid $22/hour.
- 17:15 − 8:45 = 8 h 30 min (510 minutes).
- 510 − 30 = 480 minutes = 8 h 00 min = 8.00 hours.
- 8.00 × $22 = $176.00 before tax.
Overnight: 10:00 p.m. to 6:30 a.m. → 6:30 − 22:00 = −15.5 h, + 24 = 8 h 30 min.
Minutes to decimal hours
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
Whether breaks are paid, and when overtime applies, depends on federal and state law and your employer's policy; this calculator only does the arithmetic. To turn an hourly wage into an annual salary, use the hourly to salary calculator. For 24-hour clock times, see the military time converter (24-hour clock).
Adding up a weekly timesheet
Work out each day separately, then add the decimal hours, not the clock times. Adding hours and minutes directly is error-prone because minutes roll over at 60, not 100.
| Day | In | Out | Break | Hours |
|---|---|---|---|---|
| Mon | 8:45 | 17:15 | 30 min | 8.00 |
| Tue | 9:00 | 17:30 | 30 min | 8.00 |
| Wed | 8:30 | 16:15 | 45 min | 7.00 |
| Thu | 9:10 | 18:00 | 30 min | 8.33 |
| Fri | 8:00 | 14:20 | 0 min | 6.33 |
| Total | 37.67 | |||
37.67 hours is 37 hours 40 minutes (0.67 × 60 ≈ 40). Multiply the total decimal hours by the hourly rate for gross pay.
Common mistakes
- Treating 7:30 as 7.3 hours. 30 minutes is half an hour, so 7 h 30 min = 7.5 hours.
- Forgetting to subtract the break. Only unpaid breaks come off; paid rest breaks stay in.
- Overnight shifts. Subtracting 22:00 from 06:00 gives a negative number; add 24 hours (this calculator does it automatically).
Caveats and assumptions
- Handles a single shift of up to 24 hours.
- Does not apply overtime, rounding or break laws.
- Daylight-saving changes on the night of the shift are not adjusted.
Frequently asked questions
How do I calculate hours worked?
Subtract the start time from the end time, subtract unpaid breaks, then divide minutes by 60 for decimal hours.
How do I convert minutes to decimal hours?
Divide by 60. 45 minutes = 0.75 hours; 20 minutes = 0.33 hours.
How do I calculate an overnight shift?
If the end time is earlier than the start, add 24 hours to the difference. 10 p.m. to 6 a.m. is 8 hours.
What is 8:45 to 5:15 in hours?
8.5 hours, or 8 hours after a 30-minute unpaid lunch.
How do I convert decimal hours back to minutes?
Multiply the decimal part by 60. 7.75 hours = 7 hours 45 minutes.
How many hours is 9 a.m. to 5 p.m.?
8 hours, or 7.5 hours after a 30-minute unpaid lunch.
How many hours is 7 a.m. to 3:30 p.m.?
8.5 hours (8 hours 30 minutes) before breaks.
Does this calculator handle overtime?
No. It calculates the time worked and straight-time pay only. Overtime rules depend on the law where you work and on your employer.
Sources
- NIST — Times of Day FAQs — noon/midnight conventions and the 24-hour clock
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