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Time calculator: add, subtract and find the time between
Add or subtract hours, minutes and seconds, or enter a start and end time to get the duration, including overnight shifts, with a decimal-hours answer for timesheets.
The short answer: to add times, add the minutes, carry every 60 into an hour, then add the hours: 8 hours 45 minutes plus 3 hours 30 minutes is 12 hours 15 minutes. To find the time between two clock times, subtract the earlier from the later: 9:15 AM to 5:45 PM is 8 hours 30 minutes.
Time duration examples
| Start | End | Duration | Decimal hours |
|---|---|---|---|
| 9:15 AM | 5:45 PM | 8 h 30 min | 8.5 |
| 9:00 AM | 5:30 PM, 30-minute break | 8 h 0 min | 8 |
| 10:00 PM | 6:00 AM (next day) | 8 h 0 min | 8 |
| 7:30 AM | 3:15 PM | 7 h 45 min | 7.75 |
Minutes to decimal hours
| Minutes | Decimal hour |
|---|---|
| 15 | 0.25 |
| 30 | 0.5 |
| 45 | 0.75 |
| 20 | 0.33 |
| 40 | 0.67 |
How the time calculator works
Everything is converted to seconds: hours × 3,600 + minutes × 60 + seconds. The two values are added or subtracted, and the total is converted back into hours, minutes and seconds. For clock times, minutes after midnight are subtracted, and 24 hours is added when the end is earlier than the start. Subtracting a larger time from a smaller one shows a negative result.
Use it for hours worked and pay
Multiply decimal hours by your hourly rate: 8.5 hours at $20 an hour is $170. Track pay against your bills with a paycheck budget planner, or see how long it takes to reach a date with the weeks to months converter and weeks left in the year.
Know what each paycheck covers
Turn hours into a budget
The Paycheck Budget Spreadsheet splits each paycheck across bills, savings and spending so your hours worked have a plan.
Questions, answered
How do you add hours and minutes? Add the minutes first, then the hours. If the minutes total 60 or more, carry 1 hour for every 60 minutes. For 8 hours 45 minutes plus 3 hours 30 minutes, 45 + 30 = 75 minutes, which is 1 hour 15 minutes, and 8 + 3 + 1 = 12 hours, so the answer is 12 hours 15 minutes.
How do you calculate the time between two times? Convert each time to minutes after midnight and subtract the earlier from the later. From 9:15 AM (555 minutes) to 5:45 PM (1,065 minutes) is 510 minutes, which is 8 hours 30 minutes. If the end time is earlier than the start, the calculator treats it as the next day.
How do you calculate hours worked across midnight? Add 24 hours to the end time before subtracting. From 10:00 PM to 6:00 AM, that is 30:00 minus 22:00, or 8 hours. The time duration box in this calculator does this automatically when the end time is earlier than the start time.
How do you convert hours and minutes to decimal hours? Divide the minutes by 60 and add the result to the hours. 8 hours 30 minutes is 8 + 30/60 = 8.5 hours, and 7 hours 45 minutes is 7.75 hours. Payroll systems often use decimal hours, so use that figure when you multiply by an hourly rate.
How do you subtract a lunch break from hours worked? Find the total time between clock-in and clock-out, then subtract the break. From 9:00 AM to 5:30 PM is 8 hours 30 minutes, and taking out a 30-minute unpaid lunch leaves 8 hours.
How many minutes are in an hour and seconds in a day? There are 60 minutes in an hour and 60 seconds in a minute, so an hour has 3,600 seconds. A day has 24 hours, which is 1,440 minutes or 86,400 seconds.
Does this time calculator handle daylight saving time or time zones? No. It does plain clock arithmetic and assumes no clock change between the two times. On the nights clocks change, a shift can be an hour longer or shorter than the clock difference.
Is my information saved? No. The math runs in your browser and nothing is sent or stored.