Hours Calculator
Find the hours between a start and end time, subtract unpaid breaks, and handle overnight shifts — results in hh:mm and decimal hours.
daily-life
Adjust the inputs below
Ready when you are
Adjust the inputs on the left to see your duration.
The hours calculator answers a question everyone asks at some point: "how many hours is 9 to 5?" Set a start time, an end time, and any unpaid break, and you get the elapsed time three ways — as hh:mm (like 7:30), as decimal hours (7.50), and as total minutes (450).
How it's calculated
minutes = (end − start) × 60
if end ≤ start: minutes += 1440 (overnight shift)
minutes = minutes − unpaid break (floored at 0)
hh:mm = minutes ÷ 60 hours, remainder minutes
decimal = minutes ÷ 60
Overnight shifts. If the end time is earlier than (or equal to) the start time, the calculator assumes you crossed midnight and adds 24 hours. A 10:00 PM to 6:00 AM shift correctly computes as 8 hours, not −16.
hh:mm vs decimal hours. Both formats describe the same duration, but they are read differently. 7:30 means 7 hours 30 minutes; the decimal equivalent is 7.50 because 30 minutes is half an hour. Payroll systems, invoices, and timesheet software almost always want decimal hours, since pay = decimal hours × hourly rate. The classic mistake is treating 7:30 as 7.3 hours — that silently drops 12 minutes.
Quarter-hour steps. The time sliders move in 15-minute increments because quarter-hour rounding is the most common timesheet convention in US workplaces (the FLSA permits rounding to the nearest quarter hour as long as it doesn't systematically shortchange employees). The break slider moves in 5-minute steps up to 3 hours.
Assumptions and limitations. The calculation spans at most 24 hours — it measures one shift, not multiple days. It doesn't apply overtime rules, pay rates, or time zones, and it treats the break as fully unpaid. To total a full week of shifts with overtime at 1.5x over 40 hours, use the time card calculator; to turn the hours into take-home pay, use the paycheck calculator.
Frequently asked questions
How many hours is 9 to 5?
9:00 AM to 5:00 PM is 8 hours of elapsed time. With a typical 30-minute unpaid lunch, that is 7:30 — i.e. 7.5 paid hours or 450 minutes.
How does the calculator handle overnight shifts?
If the end time is at or before the start time, it assumes you crossed midnight and adds 24 hours. So 10:00 PM to 6:00 AM computes as 8 hours.
How do I convert hh:mm to decimal hours?
Divide the minutes by 60 and add them to the hours: 7:30 = 7 + 30/60 = 7.50 hours. Payroll systems multiply decimal hours by your hourly rate.
Why do the time sliders move in 15-minute steps?
Quarter-hour rounding is the most common US timesheet convention, and the FLSA permits rounding to the nearest 15 minutes as long as it is neutral over time. It also keeps the math clean: each step is exactly 0.25 hours.
Is the break subtracted automatically?
Yes — whatever you set on the unpaid break slider is removed from the elapsed time. If your break is paid, leave the slider at 0.
Related calculators
Time Card Calculator
Add up your weekly work hours from daily clock-in/out times and breaks, with overtime at 1.5x after 40 hours — totals in both hh:mm and decimal hours.
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Paycheck Calculator
Estimate your take-home pay per paycheck after 2026 federal income tax, Social Security, Medicare, state tax, and pre-tax deductions.