Time Duration Calculator – Hours and Minutes Between Two Times
Time Duration Calculator
Quick answer
A time duration calculator finds how much time passes between a start time and an end time. Subtract the start from the end, and if the end is earlier, add 24 hours because it falls on the next day. For example, 9:00 AM to 5:30 PM is 8 hours 30 minutes, or 8.50 decimal hours. This tool does it for you, deducts breaks and also adds or subtracts time from a clock time.
Our free time duration calculator is handy for timesheets, shift work, travel times, study sessions and cooking. It works with seconds, handles overnight times correctly and converts every answer into the decimal hours most payroll systems ask for.
How to Calculate the Duration Between Two Times
The method is the same one you would use on paper. Convert both times to the 24-hour clock, subtract the start from the end, and borrow 60 minutes from the hours whenever the minutes go negative. If the result is negative, the end time is on the following day, so add 24 hours.
| Start | End | Working | Duration |
|---|---|---|---|
| 9:00 AM (09:00) | 5:30 PM (17:30) | 17:30 - 09:00 | 8 h 30 min |
| 8:45 AM (08:45) | 12:20 PM (12:20) | 12:20 - 08:45 = 11:80 - 08:45 | 3 h 35 min |
| 10:00 PM (22:00) | 6:00 AM (06:00) | 06:00 - 22:00 + 24:00 | 8 h 00 min |
| 1:15 PM (13:15) | 1:15 PM next day | 24:00 | 24 h 00 min |
For the last row, enter the same start and end time and the calculator shows 0:00:00, because it measures times within one 24-hour cycle. For gaps that span several days, use a date difference calculator instead.
How to Use the Time Duration Calculator
Step 1: Enter the Start and End Time
Open the time duration calculator and stay on Between two times. Type the start time and the end time, for example 09:00 and 17:30. The answer appears straight away as 8:30:00, which is 8 hours 30 minutes.
Step 2: Pick a Preset and Deduct Breaks
Click a preset such as 10 PM to 6 AM (night shift) to fill both times. If the end time is earlier than the start, the calculator counts it as the next day. Type your unpaid break in minutes, for example 30, and it is taken off the total.
Step 3: Read the Duration and Decimal Hours
The dark panel shows the duration as hours:minutes:seconds and in words. Below it you get decimal hours, total minutes, total seconds and the share of a 24-hour day. The night shift with a 30 minute break gives 7:30:00, 7.50 hours and 450 minutes. Click Copy result to copy it.
Step 4: Add or Subtract Time from a Clock Time
Switch to Add / subtract time to work out when something ends. Enter a start time, choose Add or Subtract and type the duration in hours, minutes and seconds. 2:15 PM plus 2 hours 45 minutes gives 5:00 PM. If the result passes midnight, the calculator shows +1 day or -1 day.
Converting Minutes to Decimal Hours
Payroll and invoicing software usually want hours as a decimal, not as hours and minutes. To convert, divide the minutes by 60 and add them to the whole hours. 7 hours 45 minutes becomes 7 + 45 / 60 = 7.75 hours. The table shows the common values.
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 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 |
A common mistake is reading 7:30 as 7.30 hours. 7 hours 30 minutes is 7.50 decimal hours, so paying 7.30 hours would short the worker 12 minutes.
Where a Time Duration Calculator Helps
- Timesheets: work out hours for each shift, take off the lunch break and copy the decimal total into payroll.
- Night shifts: 10 PM to 6 AM and other shifts that cross midnight are counted correctly without extra steps.
- Billing clients: turn a session from 2:10 PM to 3:55 PM into 1.75 billable hours.
- Travel and events: check how long a flight, train or meeting lasts, or when it will end.
- Cooking and study: add a duration to the current time to see when the oven or a study block will finish.
Time Duration Calculator Tips
- Use the 24-hour clock if you are unsure about AM and PM. 12:00 is noon and 00:00 is midnight.
- Click Use current time to fill the end time with the time right now, which is useful for tracking how long you have been working.
- Only enter unpaid breaks. Paid breaks are part of working time and should stay in the total.
- For a weekly timesheet, calculate each day, then add the decimal hours together.
All calculations run in your browser, so nothing you type is sent anywhere. The time duration calculator is free, has no sign-up and works on phones, tablets and computers.
Frequently Asked Questions
How do I calculate the time between two times?
Subtract the start time from the end time using the 24-hour clock. If the answer is negative, add 24 hours because the end is on the next day. 9:00 to 17:30 is 8 hours 30 minutes.
How do I calculate hours for a night shift?
Enter the start and end time as normal, for example 22:00 and 06:00. The calculator sees that the end is earlier and adds a day, giving 8 hours.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add the result to the hours. 8 hours 15 minutes is 8.25 hours, and 8 hours 30 minutes is 8.50 hours.
Can I subtract a lunch break?
Yes. Type the unpaid break in minutes and it is taken off the duration. A 9:00 to 17:30 day with a 30 minute break gives 8 hours.
How do I add hours to a time?
Choose Add / subtract time, enter the start time and the hours and minutes to add. 2:15 PM plus 2 hours 45 minutes is 5:00 PM.
Does it work with seconds?
Yes. Both modes accept seconds, and the result shows hours, minutes and seconds plus total seconds.
Is this time duration calculator free?
Yes. It is free, needs no account and runs entirely in your browser.