What to select
Enter a start time and end time, with an optional break. An earlier end time is treated as the following day.
Time Duration Calculator
Measure elapsed time and subtract an optional break.
We use reasonable safeguards to help protect your files and information while you use the service.
Supported formats
Arithmetic expressions, percentages, powers, square roots, numbers, calendar dates, clock times and common measurement units.
Limits and safety
Standard calculations are limited to 256 characters. Results use JavaScript floating-point arithmetic; verify financial, legal or time-sensitive decisions independently.
Frequently asked questions
Are my calculation values saved?
No. Calculator inputs and results stay in this browser tab.
Can I rely on these results professionally?
Use them as general estimates. Lenders, billing systems, calendars and rounding rules may produce different results.