Time Calculator
Add, subtract and convert time durations.
Result
ℹ️ About Time Calculator
The Time Calculator is a free online time utility that works in any modern browser. Add, subtract and convert time durations. Use it to plan events, manage productivity, track moments, or simply display time in a clean, readable way. The Time Calculator updates in real time, respects your time zone preferences, and continues to run even if you leave the tab open in the background. Perfect for students, professionals, gamers, streamers, and anyone who wants a reliable, distraction-free tool.
💡 Use Cases
📋 How to use
Pick a mode tab at the top: Add Time, Subtract Time, Time Between or Convert.
In Add Time or Subtract Time, fill the Start Time boxes for days, hours, minutes and seconds, then the same four boxes under Time to Add.
Click the Add Time or Subtract Time button to get the combined duration and its value in total seconds.
For Time Between, set Start Date/Time and End Date/Time in the two pickers and click Calculate Difference.
For Convert, enter a Value and choose From and To units among seconds, minutes, hours, days, weeks, months and years, then click Convert.
Read the answer in the Result panel; in Time Between mode it also splits the gap into years, months, days, hours and minutes.
💎 Pro Tips
- Leave the Time Calculator open in a pinned tab to keep it visible while working or studying.
- Use full-screen mode for presentations, streams, or public displays.
- Double-check your time zone if results look off — browsers default to the local system time zone.
- Bookmark the Time Calculator for quick access — it loads instantly and needs no setup.
- Combine the Time Calculator with our other time tools (world clock, countdown, timer) to build a full scheduling workflow.
❓ Frequently Asked Questions
Yes, fully free, with no signup, no ads on the interactive area, and no limits.
No. The Time Calculator keeps running as long as the tab is open, even in the background.
After the first load, the Time Calculator can usually continue to run without an internet connection.
Yes. The Time Calculator uses your browser's detected time zone by default, and most variants allow you to switch manually.
Many time tools on FreeWebTools support embedding via an iframe. Check the Embed panel on the tool page for ready-to-paste code.
The Time Calculator syncs with your system clock, so it is as accurate as your device's time settings.