Time Duration Calculator (Hours Between Two Times)

How to Use

Enter a start time and an end time using the time pickers. The duration between them is shown instantly in hours, minutes, and seconds, plus total seconds, total minutes, and decimal hours (useful for time sheets and billing). When the end time is earlier than the start time, the tool assumes the range crosses midnight and adds 24 hours; uncheck the overnight option to require strict ordering instead.

What This Tool Does

Calculates the elapsed time between two clock times within a single day (or across midnight when the overnight option is on). It does not handle dates — for spanning more than 24 hours or specific calendar dates, use a date difference calculator. Times can be entered as HH:MM or HH:MM:SS in 24-hour format. The same input/output works for any time zone since the calculation is purely arithmetic.

Output Formats

The result is shown in three forms: a human-readable "Xh Ym Zs" formatted string; raw counts (total seconds and total minutes) for scripts and integrations; and decimal hours (e.g., 1h 30m → 1.5) which is the format payroll systems and most time-sheet apps expect. All values are derived from the same difference, so they always agree exactly.

Common Use Cases

• Filling out timesheets — calculate billable hours for the day from clock-in / clock-out times.
• Estimating work-shift duration when the shift crosses midnight (e.g., 10 PM → 6 AM).
• Cooking and oven timing: how long has it been since I started?
• Sleep tracking: how long was I in bed last night?
• Calculating the duration of recordings, meetings, or sports events from start/end timestamps.

Tips

• Enter times in 24-hour format (e.g., 22:00 for 10 PM) — most browsers' time pickers accept both formats automatically.
• For overnight ranges (end < start), make sure the overnight checkbox is on.
• Decimal hours are what payroll systems use: 90 minutes is 1.5 hours, not 1.30.
• This tool ignores dates entirely. If your range covers more than 24 hours, use a date difference calculator.
• Including seconds (HH:MM:SS) is optional but useful for athletic timing or recording length checks.

Privacy

All time calculations happen in your browser. The times you enter are never sent to any server or stored anywhere.