Calculate elapsed time
The window is 2h 45m. After subtracting 15 break minutes, usable time is 2h 30m.
How it works
The calculator converts the start and end times into minutes, subtracts the start from the end, optionally handles an overnight end time, then subtracts any break minutes.
Example interpretation
A session from 09:30 to 12:15 is 2 hours and 45 minutes. If you subtract a 15-minute break, the usable planning time becomes 2 hours and 30 minutes, or 2.5 decimal hours. Decimal hours are useful when comparing the result with a study-hour target or assignment workload estimate.
Limitations
- The calculator does not know whether the full time block was focused or productive.
- Overnight mode assumes the end time is on the next calendar day.
- For multi-day schedules, use a deadline or study-time planner instead of one start/end pair.
FAQ
What does overnight mode do?
Overnight mode treats an end time earlier than the start time as happening on the next day.
Why show decimal hours?
Decimal hours are useful when comparing the result with study targets, hourly estimates, or planning spreadsheets.
Does the calculator track productivity?
No. It only calculates elapsed usable time based on the inputs. Focus and quality still need personal judgment.
Privacy note
The calculator runs in the browser and does not require an account. Inputs such as start time, end time, and break minutes are normal planning values.