Add Time Calculator
Add hours and minutes to any start time to find the end time.
How to use this tool
- Enter start time, add hours and add minutes in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your result time and the full breakdown beneath it.
Add hours and minutes to any start time to find the end time.
How it works
Enter a start time and a duration in hours and minutes, and this calculator tells you the resulting end time. It handles rollovers past midnight automatically, so adding 5 hours to 22:00 correctly gives 03:00 the next day.
This is the reverse operation of the time-duration calculator. Instead of asking how long it is between A and B, you are asking: if I start at A and spend X hours Y minutes, when do I finish? Both 12-hour AM/PM and 24-hour input formats are supported.
Typical uses include scheduling (the meeting starts at 10:15 and lasts 1 hour 45 minutes — when does it end?), cooking, medication timing, travel planning (flight departs 07:50 and takes 9 hours 10 minutes), and shift scheduling.
To subtract time instead — for example, to find what time you need to start to finish by a deadline — use a time subtraction calculator or work backwards with the time-duration tool in reverse.
Worked examples
Find meeting end time from start and length
- Enter Start time: 10:15.
- Enter Hours to add: 1, Minutes to add: 45.
- The calculator adds the duration: 10:15 + 1h 45m.
- Result: 12:00 — the meeting ends at noon.
The meeting that starts at 10:15 and runs 1 hour 45 minutes ends at exactly 12:00.
Calculate arrival time for a long flight
- Enter departure time: 07:50.
- Enter flight duration: 9 hours 10 minutes.
- Result: 17:00 local time (same-timezone example).
A 9h 10m flight departing at 07:50 lands at 17:00 (ignoring timezone changes).
Common mistakes to avoid
- Entering the duration in decimal hours (e.g. 1.5) instead of hours and minutes (1 hour 30 minutes), producing a wrong result.
- Forgetting that the result time may be on the next calendar day when the sum exceeds midnight.
- Using this for cross-timezone travel planning — the tool adds clock time only and does not account for timezone changes during a flight.
Key terms
- Time addition
- The arithmetic operation of adding a duration (hours and minutes) to a clock time to find a new clock time.
- Midnight rollover
- When adding time produces a result past 24:00, the clock wraps to the next day. 23:30 + 1 hour = 00:30 (next day).
- Duration
- A length of time expressed in hours and minutes, as opposed to a specific clock time.
Frequently asked questions
- What if the result goes past midnight?
- The result wraps around to the next day, e.g. 23:00 + 2h = 01:00.