Time Duration Calculator – Hours Between Two Times

Find the exact hours and minutes between any two times. This free time duration calculator handles overnight shifts automatically and can deduct your break for true working hours.

How to Use the Time Duration Calculator

Pick your start time and end time using the time pickers, then press Calculate Duration. The result shows the duration as hours and minutes, as decimal hours (useful for timesheets and billing), and as total minutes. If your end time is earlier than your start time — say 10:00 PM to 6:00 AM — the calculator assumes an overnight shift and adds 24 hours rather than giving you a negative answer.

The optional break field deducts unpaid time: enter 60 for a one-hour lunch and the result is your true working time. The break can never equal or exceed the total shift — the tool will tell you if it does.

How the Calculation Works

Both times are converted to minutes since midnight, then subtracted. The overnight rule is the only subtlety:

So 22:00 to 06:00 becomes (360 − 1,320) + 1,440 = 480 minutes = 8 hours. A 30-minute break then gives 7 h 30 min net, or 7.50 decimal hours. Decimal hours are what payroll systems want: 7.5 × hourly rate is trivial, while 7 h 30 min × rate invites arithmetic slips.

Worked Example

A security guard works 10:00 PM to 6:00 AM with a 30-minute break:

At $25/hour, that shift pays 7.5 × 25 = $187.50. Without the overnight rule, step 3 would have produced −960 minutes — the classic error this calculator exists to prevent.

Shift-Work and Overtime Examples — Beyond the Basics

Two practical tips. First, split shifts: calculate each block separately and add the results — the tool handles one continuous block at a time. Second, overtime disputes: screenshot or note the decimal-hours figure each week; "7.50 hours × 6 days = 45 hours" is unambiguous in a way "about seven and a half" is not, and it matches how most payroll software records time.

Limitations

The calculator assumes a single continuous block of at most 24 hours — multi-day durations belong in the date difference calculator. It does not know about public holidays, weekends or different overtime rates; it gives you hours, and your pay rules turn hours into dollars. Time inputs have minute precision, so seconds are ignored. The tool uses plain clock arithmetic, so daylight-saving transitions — which most US states observe — are not modeled: durations measured across a spring-forward or fall-back change won't be adjusted for the lost or gained hour.

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