Elapsed Time Calculator
Use this elapsed time calculator to find how much time passed between two clock times, and see the steps.
- Free
- No sign-up
- Steps shown two ways
- Finds start or end time
Elapsed time calculator
Type times like 8:05, 805, or 20:05.
Elapsed time
Count-up method
Subtraction method
What elapsed time means
Elapsed time is the amount of time that passes between a start time and an end time. If a movie starts at 7:15 PM and ends at 9:05 PM, the elapsed time is 1 hour 50 minutes.
School problems usually ask one of three things: how long something took, when it ended, or when it started. The tabs at the top of the calculator match those three questions. For practice, try these elapsed time word problems with answers. Each one opens here with the times filled in.
Two ways to work it out
Both methods below use the same problem, 5:45 AM to 4:10 PM, and reach the same answer.
Count up
Jump to the next full hour, count whole hours, then count the minutes left, and add the jumps.
- 5:45 AM to 6:00 AM: 15 minutes.
- 6:00 AM to 4:00 PM: 10 hours.
- 4:00 PM to 4:10 PM: 10 minutes.
- Add: 15 minutes + 10 hours + 10 minutes = 10 hours 25 minutes.
Subtract
Write both times in 24-hour form and subtract the minutes, then the hours, borrowing when needed.
- Write 24-hour times: 16:10 and 05:45.
- 10 − 45 won't work, so borrow 1 hour: 16:10 becomes 15:70.
- Minutes: 70 − 45 = 25. Hours: 15 − 5 = 10.
- Answer: 10 hours 25 minutes.
On a number line, the count-up jumps look like this:
If the end is earlier in the day than the start, the end is the next day. Add 24 to the end hour before you subtract.
Example problems
5:45 to 4:10, no AM or PM given. If it's 5:45 AM to 4:10 PM, the answer is 10 hours 25 minutes. If it's 5:45 PM to 4:10 AM the next morning, it's also 10 hours 25 minutes, because both spans run the same distance around the clock.
8:00 AM to 11:30 AM. 3 full hours to 11:00, then 30 minutes, so 3 hours 30 minutes.
Elapsed time questions
What is the elapsed time between 5:45 and 4:10 PM?
From 5:45 AM to 4:10 PM is 10 hours 25 minutes: 15 minutes to 6:00 AM, 10 hours to 4:00 PM, and 10 more minutes to 4:10 PM. If the start was 5:45 PM the day before, it's 22 hours 25 minutes.
How much elapsed time is there from 7:20 AM to 11:05 AM?
3 hours 45 minutes. Count 40 minutes from 7:20 to 8:00, 3 full hours from 8:00 to 11:00, then 5 minutes from 11:00 to 11:05.
How do you find elapsed time across noon?
Count up to 12:00 noon, then keep counting from noon to the end time. From 10:40 AM to 1:15 PM is 20 minutes to 11:00, 1 hour to 12:00, 1 hour to 1:00, and 15 minutes to 1:15, which adds up to 2 hours 35 minutes. In 24-hour time you can just subtract: 13:15 − 10:40.
How do you find elapsed time across midnight?
Count up to midnight, then add the time after midnight. From 9:30 PM to 2:00 AM is 2 hours 30 minutes to midnight plus 2 hours, so 4 hours 30 minutes. With subtraction, add 24 hours to the end time first: 26:00 − 21:30 = 4:30.
How do you calculate elapsed time manually?
Count up from the start in hour and minute jumps, or write both times in 24-hour form and subtract; the Two ways to work it out section above shows both methods on the same example.
Related tools
- Time duration calculatorJust the number, plus a mode for spans across several days.
- Timer calculatorAdd or subtract several durations at once.
- Military time converterSwitch any time to 24-hour form for the subtraction method.
The elapsed time calculator on TimerCalculator.com was built by Cedrick Reese. It shows two standard school methods, counting up and subtracting with borrowing, and both are worked out from the same times so they always reach the same answer. When this version was prepared, an automated browser test entered 8:00 AM to 11:30 AM and 5:45 AM to 4:10 PM and checked that both methods ended on 3 hours 30 minutes and 10 hours 25 minutes, and that an end time past midnight was labeled as the next day.