Elapsed Time Calculator
Find the time between two clock times — or how long it has been since a start time to now. Overnight shifts are handled automatically, with results in hours and minutes, decimal hours, and total minutes.
Counting hours between two times with breaks? Use the Hours Calculator. Need days, dates or time zones? Use the Time Duration Calculator.
Quick answer — elapsed time is the amount of time between two events or clock times, calculated as Elapsed Time = End Time − Start Time. The same idea is also called a time span or time length — how long between two moments.
Tip: type times without the colon — 915 = 9:15, 9 = 9:00. Leave End blank to count up to the current time (live). Overnight (10:00 PM → 6:00 AM) is handled automatically.
- Enter the start time — the clock reading when the activity began (e.g. 9:00 AM). Tap Now to fill your current time instantly.
- Enter the end time — when it finished (e.g. 5:30 PM). Leave it blank to count up to the current time — the result updates live every second.
- Read the result — hours and minutes, decimal hours and total minutes all at once. Copy it with one click.
- Overnight shifts are automatic — enter 10:00 PM to 6:00 AM and the tool adds 24 hours (8 hours, marked overnight).
How to Calculate Elapsed Time — Step by Step
- Enter the start time — the clock reading when the activity began (e.g. 11:15 AM).
- Enter the end time — the clock reading when it finished (e.g. 6:00 PM). Leave it blank to use the current time.
- The tool calculates the difference — hours and minutes between the two clock readings.
- Overnight shifts are automatic — if the end time is earlier than the start time, the tool adds 24 hours (10:00 PM → 6:00 AM = 8 hours).
The formula is simple: elapsed time = end time − start time. When the minutes are not enough, borrow one hour (60 minutes) — exactly like column subtraction. Here is the classic example with borrowing (11:15 AM → 6:00 PM):
| Step | Calculation |
|---|---|
| 1. Convert to 24-hour | 11:15 AM → 11:15; 6:00 PM → 18:00 |
| 2. Borrow for minutes | End minutes 00 < start minutes 15 → 18:00 becomes 17:60 |
| 3. Subtract hours | 17 − 11 = 6 hours |
| 4. Subtract minutes | 60 − 15 = 45 minutes → 6 hours 45 minutes |
Worked Examples
| Example | Calculation | Result |
|---|---|---|
| 11:15 AM → 6:00 PM (borrowing) | 18:00 − 11:15 → borrow 1 hour: 17:60 − 11:15 | 6 hours 45 minutes |
| 3:40 AM → 2:00 PM (vertical borrowing) | 14:00 → 13:60 − 3:40 | 10 hours 20 minutes |
| 10:00 PM → 6:00 AM (overnight) | end < start → +24 hours: (6+24) − 22 | 8 hours (overnight) |
| 8:30 AM → now (live) | leave End blank — counts up to the current time | updates live every second |
| 8:13 → 16:55 (24-hour / military) | 16:55 − 8:13 = 8h 42m | 8 hours 42 minutes |
| 12:30 PM → 2:00 PM (12 o’clock rule) | 14:00 − 12:30 = 1h 30m | 1 hour 30 minutes |
The vertical example (3:40 AM → 2:00 PM): write 2:00 PM as 14:00, borrow 1 hour to get 13:60, then subtract — 13:60 − 3:40 = 10:20 = 10 hours 20 minutes.
Common Uses
| Scenario | Example |
|---|---|
| Task or activity | How long did writing that report take, from 2:00 PM to 4:45 PM? |
| Meeting duration | A meeting starts at 9:30 AM and ends at 12:00 PM. |
| Exercise sessions | A run starts at 6:00 AM and finishes at 7:15 AM. |
| Travel time | A drive departs at 8:45 AM and arrives at 11:20 AM. |
| Time since a start ("how long ago") | I started at 8:30 AM — how long has it been now? |
| Study or homework | A student tracks when homework started and finished. |
Wondering “how long has it been?” Leave the end time blank and the tool counts up to now — perfect for tracking time since a start, like a work session or a run.
Common Mistakes When Calculating Elapsed Time
1. Borrowing wrong
When the minutes are not enough, borrow 1 hour = 60 minutes (see the vertical example above).
2. Ignoring midnight
10:00 PM to 6:00 AM is not −16 hours — when the end is earlier than the start, add 24 hours (the tool does this automatically).
3. Ignoring AM/PM
11:15 AM to 6:00 PM is 6 hours 45 minutes; ignoring AM/PM gives 5 hours 15 minutes. 12 AM = midnight, 12 PM = noon.
4. Swapping start and end
Use the Swap button. 6:00 AM to 10:00 PM is 16 hours, but 10:00 PM to 6:00 AM is 8 hours (overnight) — double the difference.
5. Confusing units
6 hours 45 minutes is 6.75 hours (45 ÷ 60 = 0.75), not 6.45 hours.
Elapsed Time Calculator — FAQ
What is elapsed time?
Elapsed time is the amount of time between two events or clock times, calculated as End Time minus Start Time. This calculator shows it as hours and minutes, decimal hours and total minutes.
How do I calculate elapsed time?
Enter the start and end times and the tool subtracts start from end. For example 9:00 AM to 5:00 PM is 8 hours. Overnight (10:00 PM to 6:00 AM) adds 24 hours automatically.
How much time has passed since a time?
Leave the end time blank — the tool uses the current time and updates live, so you always see how long it has been since your start time.
How do I calculate elapsed time between two times?
The time span between two times is calculated by entering both start and end times — the tool subtracts start from end and gives hours and minutes, decimal hours, and total minutes.
What is the formula for elapsed time?
Elapsed Time = End Time − Start Time. If the end time is earlier than the start time, the activity crossed midnight and 24 hours is added.
What is 11:15 AM to 6:00 PM in elapsed time?
6 hours 45 minutes — the crossing from AM to PM and the minute borrowing are shown in the worked example above.
What is 3:40 AM to 2:00 PM in elapsed time?
10 hours 20 minutes — borrow 1 hour (60 minutes) because 2:00 PM’s minutes (00) are less than 3:40 AM’s (40).
How do I calculate elapsed time in Excel?
In Excel, =B1-A1 gives the elapsed time when B1 is the end time and A1 is the start time (the same rule as this calculator). Format the cell as time.
Is 12 AM midnight or noon?
12 AM is midnight (start of day, 00:00) and 12 PM is noon (12:00). Use "12 midnight" and "12 noon" to avoid confusion. Switch to 24-hour (military) time with the 24h toggle — 6:00 PM becomes 18:00, 12:15 AM becomes 00:15.
How many hours is 9 AM to 5 PM?
8 hours — the standard workday. If you need to deduct lunch breaks from working hours, the Hours Calculator handles breaks too.
How long is an overnight shift?
An overnight shift crosses midnight, e.g. 10:00 PM to 6:00 AM is 8 hours. The tool detects this automatically and shows "(overnight)".
Is this elapsed time calculator free?
Yes — completely free with no sign-up. All calculations run locally in your browser; your times never leave your device.
Privacy & Accuracy
Privacy
All calculations run entirely in your browser — your times never leave your device. We do not store or save any of your input or results.
Accuracy
Values are rounded to 2 decimal places for display. Overnight spans automatically add 24 hours.
Disclaimer
This calculator is designed for general time tracking and education. It should not be relied upon for payroll, overtime or other financial calculations — use a dedicated payroll tool for that.