Time Duration
Add or subtract two HH:MM:SS durations
About this calculator
The Time Duration Calculator adds or subtracts two durations entered as HH:MM:SS, H:MM, or plain minutes, and returns the normalized result with total seconds, minutes, and decimal hours. Negative results from subtraction are kept and clearly signed, and minute or second parts of 60 or more are rejected as invalid. Handy for timesheets, workout logs, media editing, and any arithmetic on clock durations.
How to use the Time Duration calculator
- Enter your values into the input fields.
- Read the result — it updates instantly as you type.
- Adjust the inputs to compare scenarios.
- Copy the page URL to share the exact calculation.
Common examples
- 2:30:15 + 1:45:50 → 04:16:05 (4.2681 hours)
- 8:00 − 6:25 → 01:35:00 (95 minutes)
- 90 min + 45 min → 02:15:00 (2.25 hours)
- 1:00:00 − 1:30:00 → -00:30:00 (negative results are kept and signed)
Frequently asked questions
How does the Time Duration calculator work?
Enter your numbers and the calculator applies the standard formula for this everyday task, showing the result and how it was reached. It handles the unit and rounding details so you do not have to.
When would I use the Time Duration calculator?
Whenever this comes up in daily life — planning, shopping, home projects, travel or work — and you want a quick, dependable answer instead of estimating or working it out by hand.
How accurate are the results?
The math runs at full precision internally and only the displayed value is rounded for readability. For real-world use the practical limit is the accuracy of the numbers you enter, not the calculation.
Can I share a specific calculation with someone else?
Yes. Every value you enter updates the URL, so copying the address bar and sharing the link reopens the exact same calculation for whoever clicks it.