Time Duration Calculator
Add or subtract hours and minutes, or find the gap between two times.
Add or subtract a duration from a time of day, or find the difference between two times — useful for totaling work hours or figuring out how long something took.
Examples
| From | To | Duration |
|---|---|---|
| 9:00 AM | 5:30 PM | 8h 30m |
| 8:15 AM | 4:45 PM | 8h 30m |
| 7:00 AM | 3:45 PM | 8h 45m |
| 10:00 PM | 6:00 AM | 8h 0m (overnight) |
When the end time is earlier than the start time, the calculator assumes it's on the next day, so overnight shifts work without any extra steps.
Converting minutes to decimal hours for timesheets
Many payroll systems want hours as a decimal rather than hours and minutes. Divide the minutes by 60:
| Minutes | Decimal hours |
|---|---|
| 15 minutes | 0.25 |
| 20 minutes | 0.33 |
| 30 minutes | 0.5 |
| 45 minutes | 0.75 |
So a shift of 8h 45m is 8.75 hours. At $20 an hour, that's 8.75 × 20 = $175.
Totaling a work day with a lunch break
Find the time between clocking in and clocking out, then subtract any unpaid break. A 9:00 AM to 5:30 PM day is 8h 30m; take away a 30-minute unpaid lunch and you worked 8h 0m. To total a full week, add each day's hours and minutes, carrying every 60 minutes over into an extra hour.
Frequently asked questions
What is this useful for?
Common uses include totaling work hours across a timesheet, figuring out how long a shift or trip lasted, or adding a duration to a start time to find an end time.
Can I subtract time?
Yes — switch to "Start time − Duration" or "Time A − Time B" mode depending on what you're calculating.
How do I calculate hours worked for an overnight shift?
Use "Time A − Time B" mode and enter the start and end times as normal. If the end time is earlier in the day than the start, the calculator counts it as the next day — 10:00 PM to 6:00 AM is 8 hours.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add the result to the hours. 7 hours 45 minutes is 7 + 45 ÷ 60 = 7.75 hours.
What time is it 8 hours after 11:00 PM?
Use "Time + Duration" mode: 11:00 PM plus 8 hours is 7:00 AM, and the result is marked "next day" so you can see it crossed midnight.