How to Calculate Hours and Minutes Between Two Times 2026 Guide

You look at the clock when you start something, check it again when you finish, and then realise that finding the exact time difference is not always as obvious as it looked.

For example, how much time is there between 9:35 AM and 2:20 PM? You can work it out mentally, but once the minutes are different, it is easy to be off by 10 or 20 minutes.

Here is a simple way to calculate the exact hours and minutes between two times without making the process unnecessarily complicated.

The basic idea: subtract the starting time from the ending time. If the ending minutes are smaller than the starting minutes, borrow one hour and turn it into 60 minutes.

1. When the Minutes Are Easy

Let us start with a simple example: 9:15 AM to 1:45 PM.

First look at the hours, then the minutes.

Example 1

Start time: 9:15 AM

End time: 1:45 PM

9:15 AM → 1:15 PM = 4 hours

1:15 PM → 1:45 PM = 30 minutes

Total duration = 4 hours 30 minutes

For timings like this, breaking the duration into hours first and minutes afterwards is often the easiest way to do it in your head.

2. What If the End Minutes Are Smaller?

This is the part that usually causes confusion.

Suppose you want to calculate the time from 9:35 AM to 2:20 PM.

You cannot simply do 20 − 35 for the minutes. Instead, borrow one hour from the ending time.

Borrowing One Hour

End time: 2:20 PM

Borrow 1 hour = 60 minutes

20 + 60 = 80 minutes

80 − 35 = 45 minutes

After borrowing, calculate the remaining hours.

Final duration = 4 hours 45 minutes

Why does this work? One hour is exactly 60 minutes. You are not adding extra time; you are simply rewriting one of the hours as minutes to make subtraction easier.

3. An Easier Mental Method

Personally, for everyday calculations, I find the “move forward” method easier than doing formal subtraction.

Take the same example: 9:35 AM to 2:20 PM.

Count Forward

9:35 AM → 10:00 AM = 25 minutes

10:00 AM → 2:00 PM = 4 hours

2:00 PM → 2:20 PM = 20 minutes

25 + 20 = 45 minutes

Total = 4 hours 45 minutes

Both methods give exactly the same answer. Use whichever feels more natural to you.

4. Calculating Between AM and PM

Another common situation is when the start time is in the morning and the end time is in the afternoon or evening.

For example, suppose the start time is 8:40 AM and the end time is 4:10 PM.

AM to PM Example

8:40 AM → 12:00 PM = 3 hours 20 minutes

12:00 PM → 4:10 PM = 4 hours 10 minutes

Total = 7 hours 30 minutes

Watch the AM and PM: 8:00 AM to 8:00 PM is 12 hours, not zero hours. AM/PM mistakes are one of the easiest ways to get a wrong result.

5. Using 24-Hour Time Makes It Easier

If AM and PM regularly confuse you, converting the times into 24-hour format can make the calculation clearer.

12-Hour Format	24-Hour Format
8:00 AM	08:00
12:00 PM	12:00
2:30 PM	14:30
6:45 PM	18:45
10:00 PM	22:00

So instead of thinking about 9:00 AM to 5:30 PM, you can think of it as 09:00 to 17:30.

The difference is 8 hours 30 minutes.

6. What If the Time Crosses Midnight?

Now suppose something starts at 11:15 PM and finishes at 2:45 AM.

The end time is on the next day, so normal same-day subtraction will not work properly.

The easiest manual method is to split the calculation at midnight.

Across Midnight

11:15 PM → 12:00 AM = 45 minutes

12:00 AM → 2:45 AM = 2 hours 45 minutes

Total = 3 hours 30 minutes

If the end time is earlier than the start time, check whether the end time actually belongs to the following day.

7. What About Exactly the Same Time?

This one depends on what you actually mean.

If something starts at 9:00 AM and ends at 9:00 AM immediately, the duration is zero.

But if you mean 9:00 AM today until 9:00 AM tomorrow, the duration is 24 hours.

A start and end time alone cannot always tell you whether identical times mean 0 hours or 24 hours. The date matters in that situation.

8. Convert the Entire Duration Into Minutes

For some calculations, it is easier to convert both times into minutes.

The formula is simple:

Minutes Since Midnight = (Hour × 60) + Minutes

For example, 10:30 AM becomes:

10 × 60 = 600

600 + 30 = 630 minutes after midnight

Now take 1:15 PM. In 24-hour format that is 13:15.

13 × 60 = 780

780 + 15 = 795 minutes after midnight

795 − 630 = 165 minutes

165 minutes is 2 hours 45 minutes.

This method is especially useful when you are building a spreadsheet, calculator or doing several time calculations together.

9. Quick Time-Difference Examples

Start	End	Duration
8:00 AM	12:00 PM	4 hours
9:15 AM	1:45 PM	4 h 30 min
9:35 AM	2:20 PM	4 h 45 min
8:40 AM	4:10 PM	7 h 30 min
10:00 PM	2:00 AM	4 hours
11:15 PM	2:45 AM	3 h 30 min

10. Which Method Should You Use?

For a quick everyday calculation, counting forward from the start time is usually enough.

If the minutes need borrowing, use the 60-minute method. If the time crosses midnight, split the calculation at midnight. And if you have several timings to calculate, converting everything into minutes can save a lot of effort.

There is no single “correct” manual method. The best method is the one that gives you the right answer without making the calculation more difficult than it needs to be.

Frequently Asked Questions

How do I find the difference between two times?

Subtract the starting time from the ending time. If the ending minutes are smaller than the starting minutes, borrow one hour and convert it into 60 minutes before subtracting.

How many hours are there from 9:30 AM to 5:00 PM?

The duration from 9:30 AM to 5:00 PM is 7 hours 30 minutes.

How many hours are there from 8:45 AM to 2:15 PM?

There are 5 hours 30 minutes between 8:45 AM and 2:15 PM.

How do I calculate time when it passes midnight?

Calculate the time from the starting point to midnight, then calculate from midnight to the ending time and add the two durations together.

Can I calculate the difference entirely in minutes?

Yes. Convert each time into minutes after midnight, subtract the starting value from the ending value, and then convert the result back into hours and minutes if needed.

Also useful:

If you are calculating an actual work shift and need to subtract lunch or other breaks, read our How to Calculate Work Hours guide.

Don't want to calculate it manually?

Enter the start and end time in our free Time Duration Calculator. It can also handle break time and overnight calculations.

Calculate Time Duration →