Time Duration Calculator
Enter a start time and an end time to get the exact duration. Overnight spans are handled automatically.
If the end time is earlier than the start, it is counted as the next day.
When you need a time calculator, not a guess
People constantly reach for a time calculator to find how long something took or will take: a work shift, a flight with a layover, a study session, a rental period, a parking stay. Doing it by hand means borrowing across the 60-minute boundary, which is where mistakes creep in. This calculator converts both times to minutes, subtracts, and converts back, so the answer is always exact.
You also get the total in minutes and in decimal hours. The decimal hours figure is useful for timesheets and billing, where 7 hours 30 minutes is entered as 7.5. The minutes total is handy for anything priced or measured per minute.
Everyday uses you might not think of
Beyond work shifts, durations come up in surprising places. Cooks time multi-stage recipes where each step has its own start and end. Travelers add up layovers to see real journey time versus time in the air. Parents track screen time limits and homework sessions. Gamers measure speedrun attempts. In each case the question is the same: how much time passed between two clock readings, and the calculator answers it without the mental borrowing that causes mistakes.
The overnight rule
When the end time is earlier than the start time, the calculator treats the end as happening the next day. A night shift from 10:00 PM to 6:00 AM reads as 8 hours, not negative 16. This covers the vast majority of real cases: shifts, sleep, flights, and events that cross midnight.
The one case it does not cover is a span longer than 24 hours, since time-only inputs carry no date. If your event runs over multiple days, use the Date Calculator for the day count and add the partial day from here.
Frequently asked questions
How do I calculate the duration between two times?
Enter the start time and the end time. The calculator subtracts the start from the end and shows the result in hours and minutes, plus the total minutes.
What if the end time is earlier than the start time?
The calculator assumes the end time is on the next day, which covers overnight shifts and events that run past midnight.
Does it account for breaks?
No, it measures the raw span between the two times. If you need to subtract a break, use the Hours Calculator, which has a break field built in.
Can I use it for times across midnight?
Yes. A start of 10:00 PM and an end of 6:00 AM is treated as an 8-hour overnight span.
Is my data stored anywhere?
No. The calculation runs entirely in your browser and your times are never uploaded, saved or shared.
How do I calculate the hours between two times?
Enter the start time and end time and the calculator returns the exact hours between times, plus the leftover minutes. For example, 9:00 AM to 5:30 PM is 8 hours and 30 minutes.
Does the time calculator handle overnight spans?
Yes. If the end time is earlier than the start time, the calculator assumes the end is on the next day. So 10:00 PM to 6:00 AM gives 8 hours, which covers night shifts and red-eye flights.