Time Duration Calculator

Calculate the exact hours and minutes between any two times of day. Handles overnight durations automatically.

Calculate Time Duration

Overnight: If end time is before start time, the calculator assumes the shift crosses midnight and adds 24 hours.

Time Duration Calculations: From Work Shifts to Event Planning

Accurately calculating the duration between two points in time is essential in countless daily and professional scenarios. Whether you are calculating hours worked for a timesheet, measuring how long a process takes, planning event schedules, tracking study sessions, or billing a client for hours, the Time Duration Calculator gives you instant, accurate results in hours and minutes.

How Time Duration is Calculated

The calculator converts both times to total minutes since midnight (HH × 60 + MM), then subtracts the start from the end. If the result is negative (meaning end time is before start time, indicating an overnight shift), it adds 1,440 minutes (24 hours) to account for the midnight crossing. The result is then divided into hours and remaining minutes.

Example: 9:00 AM to 5:30 PM = (17×60+30) − (9×60+0) = 1050 − 540 = 510 minutes = 8 hours 30 minutes.

Common Use Cases

Employee Time Tracking

Hourly employees need to calculate their worked hours for each shift for payroll purposes. If you worked from 6:45 AM to 3:15 PM with a 30-minute unpaid lunch break, calculate 6:45 to 3:15 (8h 30m), then subtract 30 minutes = 8 hours billed. Run two calculations or subtract 30 minutes from the result for breaks.

Shift Planning

Managers scheduling shifts need to ensure legal minimum hours between shifts (often 11 hours in many jurisdictions), calculate total coverage hours, and plan handovers. This tool quickly verifies any shift timing scenario.

Freelancer Billing

Freelancers billing by the hour need accurate time tracking. Calculate duration from session start to end, then multiply by your hourly rate to get the billing amount.

Frequently Asked Questions

Yes. If the end time is earlier than the start time, the calculator automatically assumes the shift crosses midnight and adds 24 hours to the calculation. For example, a shift from 11:00 PM to 7:00 AM correctly calculates as 8 hours, not a negative number.
The calculator provides total elapsed time between two points. To account for breaks, calculate the total duration first, then use the result in combination with our Time Duration Calculator for the break period, and subtract manually. Alternatively, split your shift into segments and add the durations. For example: calculate segment 1 (start to break start) + segment 2 (break end to shift end).
Divide the total minutes by 60 to get decimal hours. For example, 7 hours 45 minutes = 7 + (45/60) = 7.75 hours. Multiplying 7.75 × your hourly rate gives the exact billing amount. Many invoicing systems prefer decimal hours (7.75) rather than hours:minutes notation (7:45) for this reason.