Time Calculator
Add or subtract hours and minutes, or calculate the duration between two times. Useful for work schedules, shifts, travel plans, workouts, meetings and anything that crosses midnight.
Add or subtract time
Find what time it will be after adding or subtracting hours and minutes.
Time between two times
Calculate the duration between a start time and an end time.
Quick time calculation examples
How to add time
To add time, convert the start time to minutes, add the duration, and convert the result back to a clock time.
How to subtract time
To subtract time, remove the duration from the start time. The calculator wraps around the 24-hour clock if needed.
Time duration
To calculate duration, subtract the start time from the end time. Use the next-day option when the end time is after midnight.
Common time calculation mistakes
Forgetting midnight
If the end time is after midnight, select the next-day option. Otherwise the calculator may treat the end time as earlier than the start time.
Mixing clock time and duration
10:30 is a time of day. 10h 30m is a duration. They look similar, but they mean different things.
Using decimal hours incorrectly
1.5 hours means 1 hour and 30 minutes, not 1 hour and 50 minutes.
Free online time calculator
This time calculator helps you add or subtract hours and minutes, calculate the time between two times, and work out simple time durations without doing manual clock math.
It is useful for work schedules, shift planning, travel itineraries, school timetables, meeting planning, exercise sessions, cooking timers, breaks and everyday time calculations.
When should you use a time calculator?
Use a time calculator when the calculation involves hours and minutes rather than regular decimal numbers. Time is based on 60 minutes per hour and 24 hours per day, so ordinary subtraction can quickly become annoying, especially when a period crosses midnight.
Time Calculator FAQ
How do I add hours and minutes to a time?
Enter the start time, enter the number of hours and minutes, choose “Add time,” and the calculator will show the resulting time.
How do I subtract hours and minutes from a time?
Enter the start time, enter the duration, choose “Subtract time,” and the calculator will show the new time.
How do I calculate the time between two times?
Enter the start time and end time. The calculator subtracts the start time from the end time and shows the duration.
What if the end time is after midnight?
Select “End time is on the next day.” This is useful for shifts, travel, events and anything that crosses midnight.
Does this calculator use 24-hour time?
The browser time input may appear in either 12-hour or 24-hour format depending on your device and locale, but the calculation works the same way.
Is this time calculator free?
Yes. It is free to use and runs locally in your browser.