Everyday & Conversions
Time Duration Calculator
Find the length of time between two clock times, including durations that run past midnight.
Your inputs
Change any value to update the result instantly.
Duration
8 h 45 min
Total minutes
525 min
Decimal hours
8.75 h
From
9:30 AM
To
6:15 PM
What this calculator does
Measures the elapsed time between two clock times.
What your result means
The duration in hours and minutes, in total minutes and in decimal hours.
Formula and working
Duration = end time − start time (+ 24 h when the end time is on the next day)
- 1
Collect the inputs
Start hour (24 h) = 9 h; Start minute = 30 min; End hour (24 h) = 18 h; End minute = 15 min; Does it cross midnight? = 0
- 2
Apply the formula
Duration = end time − start time (+ 24 h when the end time is on the next day)
- 3
Result
Duration = 8 h 45 min hours
Frequently asked questions
Symbols and assumptions
- t₁
- Start time
- t₂
- Finish time
- • Times are on a 24-hour clock.
- • When the finish time is earlier than the start time, 24 hours are added.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Daylight-saving transitions inside the interval are not applied automatically.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
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