Hours Calculator
Work hours between a start time and end time, with break deduction and overnight handling.
Formula
Net = (End − Start) − Break
How to use
- 1Enter the start hour and minute (24-hour clock).
- 2Enter the end hour and minute (24-hour clock).
- 3Enter the unpaid break in minutes, or 0 if none.
- 4Read net hours and the overnight flag, updated instantly.
About this calculator
Working out the hours between two clock times sounds simple until a shift crosses midnight or you subtract an unpaid lunch. This tool handles both. Give it a start time, an end time and a break, and it returns the total span, the net working hours after the break, and a flag for whether the shift ran overnight.
Formula explained
Both times are converted to minutes from midnight. If the end is at or before the start, a full day (1,440 minutes) is added to the end, which is how an overnight shift is recognised. Net = (End − Start) − Break, never below zero. Results show as H:MM and as decimal hours (8.5 = 8 hours 30 minutes).
Worked example
9:00 to 18:00 is 9 hours. Subtract the 60-minute break for a net 8 hours, shown as 8.0. No overnight flag, since the end is later the same day.
Tips & notes
- Write decimal hours correctly: 8.5 is eight and a half hours, not 8.30.
- Keep breaks in minutes throughout, and record real clock times rather than an estimated length.
- If your workplace rounds to the nearest quarter hour, apply the same rule every day.
- For a full week with overtime, use the time card instead of a single-day total.