Time Duration Calculator

The Time Duration Calculator works out exactly how much time passes between a start time and an end time.

Enter two times in 24-hour form, such as 09:00 and 17:30, and it returns the gap broken down into hours, minutes and seconds, along with the total minutes, total seconds and a decimal-hours figure that is perfect for timesheets and payroll.

The decimal value turns awkward spans like one hour and thirty minutes into a clean 1.5, ready to multiply by an hourly rate.

Shifts that run past midnight are handled automatically.

When the end time is earlier than the start time, the calculator assumes the period wraps into the next day — so a shift from 22:00 to 06:00 correctly reads as eight hours rather than a negative result.

If you would rather treat an end-before-start as a mistake, you can switch off the overnight option and the tool will flag it instead.

Seconds are fully supported, so you can measure short intervals as precisely as long ones.

All of the arithmetic runs locally in your browser.

Nothing is uploaded, logged or stored, the tool works offline once the page has loaded, and it makes a quick, dependable helper for billing hours, planning schedules, timing tasks or checking how long an event lasted.