Time duration calculator
Calculate time duration from hours, minutes, seconds, or start and end times, with total minutes, total seconds, decimal hours, and copyable results.
Use the duration calculator for work logs, clock-in and clock-out checks, study sessions, workouts, media timing, and simple elapsed-time math. Enter hours, minutes, and seconds or use start/end times to get normalized time, total minutes, total seconds, and decimal hours.
Calculate time duration
- Choose the matching converter or calculator.
- Enter values, dates, units, grades, or time fields.
- Adjust decimals or swap units when needed.
- Copy the browser-calculated result.
Quality checklist for Time duration calculator
- Use the default example to confirm the tool matches this exact conversion or calculator task.
- Check the input value, units, dates, grades, and decimal precision before copying.
- Use deterministic browser-only results for practical estimates, not legal, medical, or financial advice.
- Open a related workflow if the next step needs another unit, date, time, or percentage calculation.
Do these converters upload my inputs?
No. UnitQuickTools runs conversions and daily calculations in your browser. The numbers and dates you enter are not sent to an application server.
Why is my result rounded?
The tool defaults to four decimal places for readability. You can increase or reduce decimals from the settings panel.
Can I use it for timesheets?
Yes. Use the start and end time fields when you need clock-time math, then copy decimal hours if a timesheet or spreadsheet expects a decimal value.
Does it handle overnight time?
Yes. In clock-time mode, an end time earlier than the start time is treated as the next day.
Site trust and freshness
Last reviewed: . UnitQuickTools keeps public tool pages, sitemap, robots policy, and AI discovery files reviewed for search and answer-engine access.