The 3-step method
Forget the clock face for a moment and work in minutes. Convert both times to minutes since midnight, subtract, and convert the answer back. Three steps:
1. Convert. Multiply the hours by 60 and add the minutes. 9:15 AM becomes 9 × 60 + 15 = 555; 5:40 PM is 17:40, so 17 × 60 + 40 = 1,060.
2. Subtract. 1,060 − 555 = 505 minutes.
3. Convert back. Divide by 60: 505 ÷ 60 = 8 with 25 left over — 8 hours 25 minutes.
If you prefer doing it directly on the two times, use the borrow-from-60 trick: subtract the minutes first, and if the end minutes are smaller than the start minutes, borrow one hour (60 minutes) from the end hours. 5:40 − 9:15: minutes first, 40 − 15 = 25; hours, 5 − 9 — borrow an hour — 17 − 9 = 8. Answer: 8h 25m. Same number, no calculator required.
Worked example: a night shift with a break
The setup: a shift from 10:00 PM to 6:00 AM with a 30-minute unpaid break. In minutes: 10:00 PM = 1,320 and 6:00 AM = 360. The end is earlier than the start, so the shift crossed midnight — add a full day (1,440 minutes) to the end: 1,800 − 1,320 = 480 minutes (8 hours).
The break: 480 − 30 = 450 minutes = 7 hours 30 minutes = 7.50 decimal hours. Prefer to skip the arithmetic? The hours between times calculator runs this exact method and paints the shift on a 24-hour timeline.
Subtracting unpaid breaks the right way
The break comes out of the span — the total clock-to-clock time — before anything else happens. Thirty unpaid minutes inside an 8-hour span leaves 7.5 paid hours. Two mistakes show up constantly: subtracting the break from the rate (it is time, not money, that the break reduces) and forgetting that a paid break is work time — if you are paid through lunch, nothing comes out of the total.
Multiple breaks just add up: two 15-minute unpaid breaks are one 30-minute deduction. Split shifts work the same way — compute each leg separately and add the nets together.
Converting to decimal hours (the payroll step)
Payroll systems store time as fractions of an hour, so the minutes have to become decimals: divide the minutes by 60. The trap everyone falls into at least once is treating minutes as hundredths of an hour — 8 hours 15 minutes is 8.25, never 8.15. Entering 8.15 undercounts by 6 minutes a day, about 26 minutes over a work week.
Memorize the quarter-hours (0.25, 0.50, 0.75) and derive the rest — they cover the vast majority of real timesheets. For everything else, the calculator's second tab converts hours and minutes with optional payroll rounding built in.
Rounding rules: what employers can do
Many employers round clock times — the most common scheme is the quarter-hour rule: clock times are rounded to the nearest 15 minutes, so 8:07 becomes 8:00 and 8:08 becomes 8:15. The key legal expectation in the US is neutrality: rounding must average out and may not systematically favor the employer. A rule that always rounds down is not rounding at all.
The practical move is to keep your own log of actual clock times and apply the employer's stated rule yourself before comparing with the paycheck. A small but consistent shortfall — one that never evens out — is the signal worth raising with HR or payroll.
Hours between times — frequently asked questions
How do I calculate hours between times that cross midnight?
Add 24 hours (1,440 minutes) to the end time before subtracting. 10:00 PM to 6:00 AM becomes 30:00 − 22:00 = 8 hours. This is the one rule that makes overnight math trivial.
What is 7:45 in decimal hours?
Divide the minutes by 60: 45 ÷ 60 = 0.75, so 7:45 = 7.75 decimal hours. For the common quarter-hours: 15 minutes is 0.25, 30 is 0.50, 45 is 0.75.
Do I subtract lunch before converting to decimals?
Yes. Convert only your net, paid time into decimals. With an 8-hour span and a 30-minute unpaid lunch, you convert 7.5 hours — never the full 8.
How do I calculate hours for a 9:00-to-9:00 shift?
Identical start and end times mean zero hours by convention — the same reading twice is no elapsed time. A genuine 24-hour shift needs to be marked as ending the next day explicitly.
What about the daylight-saving weekend?
An overnight shift spanning a spring-forward loses a clock hour; a fall-back shift gains one. Many employers have a written policy on whether you are paid scheduled or actual elapsed hours — log both and check.
How do I check my timesheet total against my paycheck?
Convert your clock times to net decimal hours using your employer's rounding rule, multiply by your hourly rate, and compare with gross pay before taxes and deductions. If overtime is involved, the overtime pay guide shows how the 1.5× premium works.
For instant answers, the hours between times calculator handles same-day and overnight shifts, unpaid breaks, and minutes-to-decimal conversion in one place — and the overtime pay calculator picks up where this guide leaves off once you cross 40 hours.