This hours calculator tells you how many hours you worked between clocking in and clocking out, with unpaid break time subtracted automatically. Type times the way you say them, since "9:00 AM", "09:00" and 24-hour "21:30" all parse, and overnight shifts that cross midnight are handled correctly.
Beyond the daily total it converts to the decimal hours payroll systems use, projects a weekly total, and estimates gross pay if you enter an hourly rate. It is the quickest way to sanity-check a paycheck or plan a schedule.
If you just want the answer for a standard shift, the table below gives the hours for 30 common start and end times, from 6am to 11pm.
Shift Hours Chart: How Many Hours from X to Y
The pattern in the chart is worth noticing, because it explains most payroll surprises. A nominal "9 to 5" is 8 hours of span but only 7.5 paid hours once an unpaid 30-minute lunch comes out, which is 37.5 hours a week rather than 40.
To actually reach a 40-hour week with an unpaid half-hour lunch, the shift has to be 8.5 hours long: 8am to 4:30pm, or 9am to 5:30pm. That half hour is worth 2.5 hours of pay a week, which at $22 an hour is $55.
Going the other way, a 9-hour span with a 30-minute lunch gives 8.5 paid hours and 42.5 a week, which means 2.5 hours of overtime for a non-exempt employee.
| Shift | Total hours | Minus 30-min lunch | Over 5 days |
|---|---|---|---|
| 6am to 2pm | 8 hours | 7.5 | 37.5 |
| 7am to 2pm | 7 hours | 6.5 | 32.5 |
| 7am to 3pm | 8 hours | 7.5 | 37.5 |
| 7am to 4pm | 9 hours | 8.5 | 42.5 |
| 8am to 2pm | 6 hours | 5.5 | 27.5 |
| 8am to 3pm | 7 hours | 6.5 | 32.5 |
| 8am to 4pm | 8 hours | 7.5 | 37.5 |
| 8am to 4:30pm | 8.5 hours | 8 | 40 |
| 8am to 5pm | 9 hours | 8.5 | 42.5 |
| 9am to 2pm | 5 hours | 4.5 | 22.5 |
| 9am to 3pm | 6 hours | 5.5 | 27.5 |
| 9am to 4pm | 7 hours | 6.5 | 32.5 |
| 9am to 5pm | 8 hours | 7.5 | 37.5 |
| 9am to 5:30pm | 8.5 hours | 8 | 40 |
| 9am to 6pm | 9 hours | 8.5 | 42.5 |
| 9am to 7pm | 10 hours | 9.5 | 47.5 |
| 10am to 4pm | 6 hours | 5.5 | 27.5 |
| 10am to 5pm | 7 hours | 6.5 | 32.5 |
| 10am to 6pm | 8 hours | 7.5 | 37.5 |
| 10am to 7pm | 9 hours | 8.5 | 42.5 |
| 11am to 7pm | 8 hours | 7.5 | 37.5 |
| 11am to 8pm | 9 hours | 8.5 | 42.5 |
| 12pm to 8pm | 8 hours | 7.5 | 37.5 |
| 2pm to 10pm | 8 hours | 7.5 | 37.5 |
| 3pm to 11pm | 8 hours | 7.5 | 37.5 |
| 7pm to 3am | 8 hours | 7.5 | 37.5 |
| 10pm to 6am | 8 hours | 7.5 | 37.5 |
| 11pm to 7am | 8 hours | 7.5 | 37.5 |
The last three rows cross midnight. An overnight shift is counted the same way: the end time simply falls on the next calendar day, so 11pm to 7am is 8 hours, not 16.
How Hours Worked Are Calculated
The arithmetic is simple once times are converted to minutes since midnight:
hours worked = (time out − time in − unpaid break) ÷ 60
A 9:00 AM clock-in is minute 540 and a 5:00 PM clock-out is minute 1,020, so the shift spans 480 minutes. Subtract a 30-minute unpaid lunch and you worked 450 minutes, which is 7 hours 30 minutes, or 7.5 decimal hours.
Converting to minutes first is the reliable way to avoid AM and PM mistakes, which are the most common error in manual timesheet maths.
When the clock-out time is earlier than the clock-in time, the calculator adds 24 hours and treats the shift as overnight, so 10:00 PM to 6:30 AM with a 30-minute break is 8 hours. A single in and out pair caps at 24 hours; use the time card calculator for a full multi-day week.
One conversion to keep straight: decimal hours are not hours and minutes. Seven hours 45 minutes is 7.75 decimal hours, not 7.45. Payroll systems use decimal, and entering 7.45 instead of 7.75 quietly underpays by 18 minutes.
Hours to Minutes, Seconds and Days
How many hours in a week and how many hours in a month come up constantly for shift planning, and only one of them has a single answer:
- A week is always 168 hours
- A month averages 730 hours, but the actual figure is 672 in February, 696 in a leap February, 720 in a 30-day month and 744 in a 31-day month
- A year is 8,760 hours, or 8,784 in a leap year
- A full-time working month averages 173 hours, from 2,080 annual hours divided by 12
The conversions tied to deadlines are the other common group. 72 hours is exactly 3 days, 48 hours is exactly 2, and 36 hours is a day and a half. Because these divide evenly by 24, a 72-hour deadline lands at the same clock time three days later.
1,000 hours is 41.67 days, or nearly six weeks. That figure comes up in warranty terms and equipment service intervals, where hours of operation rather than calendar time is what triggers the service.
A useful pair for work planning: a full-time year is 2,080 hours, and a full-time month averages about 173 hours. Dividing an annual salary by 2,080 gives the equivalent hourly rate, which is the fastest way to compare a salaried offer against an hourly one.
| Hours | Minutes | Seconds | Days |
|---|---|---|---|
| 1 hour | 60 | 3,600 | 0.042 |
| 3 hours | 180 | 10,800 | 0.125 |
| 8 hours | 480 | 28,800 | 0.333 |
| 12 hours | 720 | 43,200 | 0.5 |
| 24 hours | 1,440 | 86,400 | 1 |
| 36 hours | 2,160 | 129,600 | 1.5 |
| 48 hours | 2,880 | 172,800 | 2 |
| 72 hours | 4,320 | 259,200 | 3 |
| 100 hours | 6,000 | 360,000 | 4.17 |
| 168 hours | 10,080 | 604,800 | 7 |
| 1,000 hours | 60,000 | 3,600,000 | 41.67 |
| 2,000 hours | 120,000 | 7,200,000 | 83.33 |
There are 3,600 seconds in an hour, 60 minutes in an hour, and 86,400 seconds in a day. A week is 168 hours, and a standard full-time work year is 2,080 hours, which is 40 hours across 52 weeks.
How Many Hours Is Full Time and Part Time?
There is no single legal answer in the US, and the threshold depends entirely on which rule is being applied.
Full time:
- The Affordable Care Act defines full time as 30 or more hours a week, or 130 hours a month, and that is the figure that determines employer health-coverage obligations
- The Bureau of Labor Statistics counts 35 or more hours a week as full time for statistical purposes
- Most employers use 40 hours a week as their internal definition, which is 2,080 hours a year
- The Fair Labor Standards Act does not define full time at all. It only sets the point at which overtime begins, which is 40 hours in a workweek
Part time:
- Generally under 30 to 35 hours a week, most commonly 20 to 29
- Under the ACA, under 30 hours a week is part time for coverage purposes
- There is no federal minimum, and no federal rule requiring benefits at any level
The practical consequence is that 30 hours a week can be full time for health insurance and part time for your employer’s vacation policy at the same time, and both can be correct. If it matters, ask which definition your employer’s specific benefit uses rather than assuming a number.
For students, full time is usually 12 credit hours a semester for undergraduates, which is a separate system entirely and matters for financial aid and dependent status.
On overtime: non-exempt employees earn 1.5 times the regular rate past 40 hours in a workweek under the FLSA. The 32-hour work week proposals discussed in recent years would lower that threshold to 32, but as things stand 40 is the federal line.
Breaks and Rounding Rules
A few US rules worth knowing when tallying work hours:
- Short rest breaks of roughly 5 to 20 minutes are generally counted as paid time under federal law, so they stay in your total
- Bona fide meal periods of 30 minutes or more, where you are fully relieved of duties, may be unpaid. Only enter unpaid time in the break field
- If you are interrupted during an unpaid meal break and have to work, that time is generally compensable
- Employers may round punches to the nearest quarter hour under the so-called 7-minute rule, where 7:53 through 8:07 all become 8:00, but the rounding must not consistently favour the employer
- Several states have their own meal and rest break requirements that are stricter than federal law
If your week is not five identical days, total each day separately and add them rather than using the weekly projection.
Frequently Asked Questions
How many hours is 9am to 5pm?
Eight hours as a span, or 7.5 paid hours once an unpaid 30-minute lunch is subtracted. Over five days that is 37.5 hours, not 40. To reach a full 40-hour week with a half-hour unpaid lunch, the shift needs to run 8.5 hours, such as 9am to 5:30pm.
How many hours is 8am to 4pm?
Eight hours, or 7.5 after an unpaid 30-minute lunch, giving 37.5 hours across five days. 8am to 4:30pm is the version that produces a full 40-hour week with the same lunch break.
How many hours is 9am to 3pm?
Six hours, or 5.5 after an unpaid 30-minute break. Over five days that is 27.5 hours, which is part time under the ACA definition of 30 hours a week.
How do I calculate hours worked?
Subtract clock-in from clock-out, then subtract unpaid breaks. Convert times to minutes since midnight to avoid AM and PM errors: 8:30 AM to 4:45 PM is 990 − 510 = 480 minutes, and minus a 30-minute lunch that is 450 minutes, or 7.5 hours.
How many seconds are in an hour?
3,600. That is 60 minutes multiplied by 60 seconds. A day holds 86,400 seconds, and a 24-hour period is 1,440 minutes.
How many minutes are in 8 hours?
480 minutes. Multiply hours by 60. For reference, 3 hours is 180 minutes, 12 hours is 720, and 24 hours is 1,440.
How many days is 72 hours?
Exactly 3 days, since 72 divides evenly by 24. Put the other way round, 72 hours is how many days: three. That means a 72-hour deadline falls at the same clock time three days later. Similarly, 48 hours is 2 days and 36 hours is a day and a half.
How many hours in a month?
An average of 730, but the exact figure depends on the month: 672 hours in February, 696 in a leap February, 720 in a 30-day month and 744 in a 31-day month. A full-time working month is much lower at about 173 hours, from 2,080 annual hours divided by 12.
How many hours are in a week?
168 hours, which is 7 days multiplied by 24. That figure never varies. A standard full-time working week of 40 hours is therefore just under a quarter of the total hours available.
How many hours is part time?
Generally under 30 to 35 hours a week, most commonly 20 to 29. The Affordable Care Act treats under 30 hours a week as part time for health-coverage purposes, while the Bureau of Labor Statistics uses under 35. There is no federal minimum and no federal rule requiring benefits at any level.
How many hours is full time?
It depends which rule applies. The ACA says 30 or more hours a week, the Bureau of Labor Statistics uses 35 or more, and most employers use 40, which is 2,080 hours a year. The Fair Labor Standards Act does not define full time at all; it only sets overtime at over 40 hours in a workweek.
How many credit hours is full time?
Usually 12 credit hours per semester for undergraduates, and often 9 for graduate students. This is a separate system from employment hours and matters for financial aid eligibility, scholarships and dependent status. Check with your institution, since the threshold varies.
Do breaks count as hours worked?
Short rest breaks of about 5 to 20 minutes count as paid working time under federal rules. Bona fide meal periods of 30 minutes or more, where you are fully relieved of duties, may be unpaid. Enter only unpaid break minutes here so paid rest breaks stay in your total.
How does the calculator handle overnight shifts?
If the time out is earlier than the time in, it assumes you clocked out the next day and adds 24 hours, so 11:00 PM to 7:00 AM is 8 hours. Each entry covers a single shift of up to 24 hours; for a whole week of shifts, use the time card calculator.
How do I calculate my pay from hours worked?
Multiply decimal hours by your hourly rate, so 7.5 hours at $22 is $165 gross. Use decimal hours rather than hours and minutes: 7 hours 45 minutes is 7.75, not 7.45. Past 40 hours in a workweek, non-exempt workers earn 1.5 times the rate on the overtime hours.