Free Time Duration Calculator
Add and subtract time durations in hours, minutes, and seconds. Free, fast, and works entirely in your browser with no sign-up required.
Duration Calculator
Add and subtract time durations, convert between units, calculate time between timestamps, track work hours, find overlapping time periods, and solve speed/distance/time problems.
Duration Entries
Total Duration
All Format Conversions
Tips
• Use the "−" (subtract) button on any row to deduct that duration from the running total.
• Click a quick-preset button to instantly add a pre-configured duration row.
• Export to CSV to save your calculation for timesheets or records.
• The "All Format Conversions" panel shows your total in every unit simultaneously.
History
Quick Reference
Frequently Asked Questions
What is the Duration Calculator?
The Duration Calculator is a free online tool that adds and subtracts time durations in hours, minutes, and seconds for time tracking and scheduling.
Is the Duration Calculator free?
Yes, it is completely free with no registration required. All calculations happen client-side in your browser.
Can I add multiple durations?
Yes, the Duration Calculator lets you add and subtract multiple time durations to get a total, useful for project tracking and scheduling.
Is my data safe with this tool?
Absolutely. The Time Duration Calculator processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the Time Duration Calculator work on mobile devices?
Yes, the Time Duration Calculator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the Time Duration Calculator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
How accurate are the calculations?
The Time Duration Calculator uses industry-standard formulas and algorithms to ensure accurate results. However, for critical financial or medical decisions, always consult a qualified professional.
How do I use the Time Duration Calculator?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
Which browsers are supported?
The Time Duration Calculator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.
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About Free Time Duration Calculator
Free Time Duration Calculator is a free, browser-based tool in our Calculator Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.