Add Time Calculator
Add or subtract several durations to get a total, or add time straight onto a clock time to find what time it'll be. Pick the mode below.
Add time calculator
Total
3 hr 00 min
3.00 decimal hours
Resulting time
3:15 PM
Same day
How to add hours and minutes
Add hours to hours and minutes to minutes, then carry over any full hour out of the minutes total.
1 hr 40 min + 55 min = 1 hr 95 min → carry 60 minutes into the hours: 2 hr 35 min.
How to subtract time durations
If the minutes being subtracted are larger than the minutes on hand, borrow an hour first.
3 hr 20 min − 45 min → borrow: 2 hr 80 min − 45 min = 2 hr 35 min
Sum examples
| Durations | Total |
|---|---|
| 1 hr 40 min + 55 min + 2 hr 10 min | 4 hr 45 min |
| 3 hr 20 min − 45 min | 2 hr 35 min |
| 45 min + 45 min + 45 min + 45 min | 3 hr 00 min |
Adding time to a clock time
This is a different question from summing durations — instead of "how long in total," it's "what time will it be." Add the duration's minutes and hours onto the start time, and if the total minutes-since-midnight crosses 1,440 (24 hours), the result falls on the next day.
| Start | Change | Result |
|---|---|---|
| 9:30 AM | + 5 hr 45 min | 3:15 PM (same day) |
| 10:00 PM | + 4 hr 30 min | 2:30 AM (next day) |
| 6:00 AM | − 8 hr 00 min | 10:00 PM (previous day) |
When the total goes negative
Subtracting more than you've added produces a negative total, shown with a minus sign (e.g., "−1 hr 15 min"). That's a real answer, not an error — it just means the running total dipped below zero. If you didn't expect that, check whether a row's sign should be + instead of −.
Where this comes up
- Timesheets: adding several clocked segments (with an unpaid break subtracted) into one daily total.
- Media and production: summing clip or track lengths into a total runtime.
- Project estimates: adding task durations together, or subtracting time already spent from a budget.
- Scheduling: figuring out what time a task will finish, or when to start something to hit a deadline.
Working from actual clock-in/out punches for one shift instead of a list of durations? Calculate hours worked handles that directly. Need the gap between two known times instead of a sum? Use the time duration calculator. Have a total and need overtime pay from it? Use the overtime calculator. Want the total expressed as hours and minutes from a raw minute count instead? See the minutes to hours converter.
Frequently asked questions
How do I add hours and minutes together?
Add the hours together and the minutes together separately, then carry over: if the minute total reaches 60 or more, subtract 60 from it and add 1 to the hours. 1 hr 40 min + 55 min = 1 hr 95 min = 2 hr 35 min.
How do I subtract time durations?
Subtract hours from hours and minutes from minutes. If the minutes go negative, borrow 60 minutes from the hours column first. 3 hr 20 min − 45 min: borrow to make it 2 hr 80 min − 45 min = 2 hr 35 min.
What happens if I subtract more time than I added?
The total goes negative, and the calculator shows it with a minus sign — for example, "−1 hr 15 min." That usually means a row is wrong or you meant to subtract the total from something else, like a budget.
Can I add time directly to a clock time, like "what time is it in 3 hours"?
Yes — switch to "Add to a start time" mode, enter the start time and how much to add or subtract, and it returns the resulting clock time, noting if it lands on a different day.
Does adding past midnight roll over correctly?
Yes. Adding to a time near midnight wraps to the next day's clock time and the result says so explicitly rather than showing an ambiguous time with no date context.