Find your exact age in years, months and days from your date of birth, plus your age in days, weeks and hours and the days to your next birthday.
Time Calculator
Add or subtract hours, minutes and seconds. Find the difference between two times or add a duration to a start time.
This tool could not be loaded. Please refresh the page. If the problem continues, try a different browser.
+
Result
All calculations run in your browser. Nothing is sent to a server.
Runs entirely in your browser. Your files and text are not uploaded.
How to use Time Calculator
-
Step 1: Choose a mode
Pick Add/Subtract to combine durations, or Difference to find the gap between two clock times.
-
Step 2: Enter the times
Fill in hours, minutes and seconds for each time. Leave fields at 0 if you do not need them.
-
Step 3: Read the result
The answer updates as you type, shown as hours, minutes and seconds with the total in seconds.
How it works
Adding and subtracting durations
Everything is converted to seconds, added or subtracted, then converted back to hours, minutes and seconds. For example, 2 h 45 min + 1 h 30 min = 9,900 s + 5,400 s = 15,300 s = 4 h 15 min 0 s.
Time difference
The difference mode finds how far apart two clock times are. Enter a start time and an end time, and the calculator shows the gap. If the end time is earlier than the start time, it assumes the end time is the next day.
Handling negative results
If you subtract a larger duration from a smaller one, the result is shown as negative. The hours, minutes and seconds are the absolute value, with a minus sign in front.
Limitations
- Times are durations, not clock times with AM/PM (except in difference mode).
- Dates are not included; the calculator works with hours, minutes and seconds only.
- In difference mode, an end time earlier than the start time is assumed to be the next day.
- Your values are not saved or sent anywhere.
Frequently asked questions
Can I add more than two times?
The calculator adds or subtracts two durations at a time. For more, enter the first result into the next calculation.
What if the result is negative?
It is shown with a minus sign. The hours, minutes and seconds are the size of the difference.
Does it handle days?
Not directly. Hours greater than 24 just stay as hours. In difference mode, if the end time is before the start time, 24 hours is added automatically.
Can I use this for payroll hours?
Yes. Enter the start and end times in difference mode to find the hours worked, then total them using add mode.
Related tools
Count days, weeks, months and years between two dates, or add and subtract calendar time from a date.
Count down a set time or to a date and time, with a large full-screen display and alarm.
Calculate X% of Y, what percent X is of Y, percentage increase or decrease, reverse percentages, adding or subtracting a percentage and percentage difference.