How do I calculate the duration between two times?

To calculate time duration: 1) Convert both times to 24-hour format. 2) Subtract the start time from the end time. 3) If the result is negative, add 24 hours (for overnight). For example, 9:00 AM to 5:30 PM = 17:30 − 09:00 = 8 hours 30 minutes.

How many hours between 9 AM and 5 PM?

There are exactly 8 hours between 9:00 AM and 5:00 PM. If you mean 9 AM to 5:30 PM, that is 8 hours and 30 minutes.

How do I calculate time duration for a night shift?

For overnight or night shifts that cross midnight, enable the 'Spans overnight' option in this calculator. For example, a shift from 10:00 PM to 6:00 AM is 8 hours. The calculator automatically adds 24 hours when the end time is earlier than the start time.

How do I convert hours and minutes to decimal?

To convert time to decimal hours, divide the minutes by 60 and add to the hours. For example, 2 hours 30 minutes = 2 + (30÷60) = 2.5 hours. This is useful for payroll and billing calculations.

How many minutes are in 2.5 hours?

There are 150 minutes in 2.5 hours. To convert hours to minutes, multiply by 60. So 2.5 × 60 = 150 minutes.

Time Between Two Times Calculator

Find the exact duration between two times — hours, minutes and seconds. Works for overnight shifts, AM/PM, and 24-hour format.

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Time Difference

How long between two times?

Start Time

End Time

Does the shift span overnight?

Select "Yes" for night shifts or any shift that crosses midnight.

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Hours

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Total minutes

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Total seconds

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Add Time

What time will it be after adding hours and minutes?

Start Time

Add duration

Hours

Minutes

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Subtract Time

What time was it before subtracting hours and minutes?

Start Time

Subtract duration

Hours

Minutes

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⚡ Common time durations — quick reference

From	To	Duration
9:00 AM	5:00 PM	8 hours
9:00 AM	5:30 PM	8 hours 30 min
8:00 AM	4:00 PM	8 hours
10:00 PM	6:00 AM (+1 day)	8 hours
9:00 AM	1:00 PM	4 hours
9:00 AM	12:00 PM	3 hours
8:30 AM	5:30 PM	9 hours
12:00 PM	5:00 PM	5 hours

How to calculate time duration

Calculating the hours and minutes between two times is straightforward once you know the steps. Here's the method used by this calculator:

Step 1 — Convert to 24-hour format

AM hours are the same in both 12-hour and 24-hour format. For PM hours, add 12. For example, 1:00 PM becomes 13:00, and 5:30 PM becomes 17:30. Midnight is 00:00 and noon is 12:00.

Step 2 — Subtract start from end

Subtract the start time from the end time. If both the hours and minutes are straightforward, the subtraction is simple:

Example: 17:30 − 09:00 = 8 hours 30 minutes

Step 3 — Handle the minutes carefully

If the end minutes are smaller than the start minutes, borrow 1 hour (60 minutes) from the hours column:

Example: 13:15 − 09:45 → borrow 1 hour → 12:75 − 09:45 = 3 hours 30 minutes

Step 4 — For overnight shifts

If the end time is earlier than the start time and the shift crosses midnight, add 24 hours to the end time before subtracting:

Example: Night shift 22:00 to 06:00 → 06:00 + 24:00 = 30:00 → 30:00 − 22:00 = 8 hours

Converting to decimal hours

For payroll and billing, you may need hours in decimal format. Divide the minutes by 60 and add to the hours. For example, 7 hours 45 minutes = 7 + (45 ÷ 60) = 7.75 hours.

Frequently asked questions

There are exactly 8 hours between 9:00 AM and 5:00 PM. If the end time is 5:30 PM, the duration is 8 hours 30 minutes. Use the calculator above to get the exact result for any pair of times.

For night shifts that cross midnight — such as 10:00 PM to 6:00 AM — select the "Yes — crosses midnight" option in the calculator above. It automatically adds 24 hours to handle the day change. A 10 PM to 6 AM shift is exactly 8 hours.

Divide the minutes by 60 and add to the hours. Examples:
• 7 hours 30 minutes = 7.5 hours
• 8 hours 45 minutes = 8.75 hours
• 6 hours 20 minutes = 6.33 hours
The calculator above shows the decimal hours automatically in the result.

There are 150 minutes in 2.5 hours. Multiply hours by 60 to convert to minutes. So 2.5 × 60 = 150 minutes. Similarly, 1.5 hours = 90 minutes, 3.5 hours = 210 minutes.

There are 3,600 seconds in one hour. This is because 1 hour = 60 minutes, and each minute = 60 seconds. So 60 × 60 = 3,600 seconds per hour.

Time duration and time difference mean the same thing — the total amount of time elapsed between a start time and an end time. Both are calculated by subtracting the start from the end time.

To find the time between two specific dates and times, use our Date Difference Calculator. It calculates the exact number of days, hours, and minutes between any two date-and-time combinations.

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