How to calculate hours worked from clock-in and clock-out
The idea is simple: take your clock-out time, subtract your clock-in time, then take off any unpaid break. Where people slip up is the last step — turning the leftover minutes into the decimal hours that payroll actually runs on.
Here's a real example. Say you clock in at 8:15 in the morning and clock out at 4:45 in the afternoon, with a 45-minute unpaid lunch:
- From 8:15 to 4:45 is 8 hours and 30 minutes of elapsed time.
- Take off the 45-minute lunch and you're left with 7 hours and 45 minutes of paid time.
- Written as decimal, that's 7.75 hours — the number your employer multiplies by your pay rate.
The trap is writing "7.45" for seven hours and forty-five minutes. Minutes run to 60, not 100, so you divide them: 45 ÷ 60 = 0.75. Get it wrong and a single shift is off by real money. The calculator above handles the conversion, but it's worth understanding, because checking it yourself is the easiest way to catch a short paycheck.
Minutes-to-decimal conversion chart
If you'd rather convert in your head, here's the cheat sheet people keep coming back for:
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 min | 0.08 | 35 min | 0.58 |
| 10 min | 0.17 | 40 min | 0.67 |
| 15 min | 0.25 | 45 min | 0.75 |
| 20 min | 0.33 | 50 min | 0.83 |
| 30 min | 0.50 | 60 min | 1.00 |
How employers round your clock-in time
Most timekeeping systems don't pay to the exact minute. Under U.S. federal rules an employer can round clock times to the nearest quarter-hour, as long as the rounding doesn't consistently work against the worker. In practice that's the 7-minute rule: clock in within 7 minutes of a quarter-hour mark and it rounds back; hit 8 minutes or more and it rounds up. So 8:07 becomes 8:00, but 8:08 becomes 8:15. It's meant to even out over time — but it's worth comparing your own times to your paystub now and then, because small rounding errors in one direction add up across a year.
Overnight and graveyard shifts
A shift that crosses midnight is where the math usually breaks. Clock in at 10:00 p.m. and out at 6:00 a.m. and a plain subtraction gives you minus sixteen hours, which is obviously wrong. The fix is to treat the clock-out as belonging to the next day, so 22:00 to 06:00 comes out as a clean 8 hours. This calculator spots an overnight shift on its own — if the clock-out time is earlier than the clock-in, it assumes you finished the following morning.
When overtime starts
Under the federal Fair Labor Standards Act, non-exempt employees earn overtime — paid at time-and-a-half — for hours worked beyond 40 in a single workweek. Some states go further: California, for one, also requires daily overtime once you pass 8 hours in a day. The tool uses the 40-hour weekly threshold by default, which fits most people; change it in the options if your state or workplace is different. To see what those extra hours are worth in dollars, the overtime pay calculator breaks it down hour by hour.
A few things worth knowing
- Only deduct breaks you're not paid for. Federal rules generally treat short breaks under 20 minutes as paid time, while a genuine meal break of 30 minutes or more is usually unpaid. Take off the lunch; leave the coffee break in.
- Keep your own record. Time clocks glitch and managers fat-finger entries. A quick note of your daily in and out times is the cheapest insurance against a wrong paycheck.
- Hand in decimal, not fractions. Submit 7.75, never 7:45 — it removes any ambiguity when your hours get multiplied by your rate.
Two worked examples
A part-time week. Tuesday 9:00–2:00 with no break is 5.00 hours; Thursday 9:00–3:30 with a 30-minute lunch is 6.00 hours; Saturday 10:00–1:00 is 3.00 hours. The week totals 14.00 hours.
A full week with overtime. Five days of 8:00–5:00 with a 30-minute lunch works out to 8.5 hours a day, or 42.5 hours for the week. The first 40 are paid at your normal rate; the remaining 2.5 are paid at time-and-a-half.
Frequently asked questions
How do I calculate hours worked from clock in and clock out?
Subtract your clock-in time from your clock-out time, then take off any unpaid break, and convert the leftover minutes to decimal by dividing by 60. The calculator above does all of this for a full week and totals it.
How do I convert minutes to decimal hours?
Divide the minutes by 60. So 15 minutes is 0.25, 30 is 0.50, and 45 is 0.75. The chart above lists the common ones.
How many hours is 9 to 5?
From 9:00 a.m. to 5:00 p.m. is 8 hours of elapsed time. If your employer deducts a 30-minute or 1-hour unpaid lunch, your paid time is 7.5 or 7 hours.
Does a lunch break get deducted?
Usually yes — an unpaid meal break comes off your total. Enter it in the break column and the calculator removes it. Short paid breaks are not deducted.
How do I calculate hours for an overnight shift?
Enter the times as normal. If the clock-out is earlier than the clock-in, the tool treats it as the next morning, so an overnight shift totals correctly.
What is the 7-minute rounding rule?
It's the U.S. standard for rounding clock times to the nearest 15 minutes: within 7 minutes of the mark rounds down, 8 minutes or more rounds up. It has to be applied evenly, not only in the employer's favor.
What's the difference between a time card and a timesheet?
A time card records basic clock-in and clock-out times for payroll. A timesheet usually adds detail like the project or task worked on. For totalling hours and pay, they come to the same thing.
How do I total hours for a two-week pay period?
Calculate each week on its own, then add them. Overtime is figured per week — 40 hours one week and 45 the next means 5 overtime hours, not zero.
Can I use this to check my paycheck?
Yes. Add up your own clock times here, multiply by your rate, and compare it against your paystub. It's the quickest way to spot an underpayment.
How many hours are common work shifts?
Here are the everyday ones, shown as paid hours after a typical 30-minute unpaid lunch:
| Shift | Elapsed | Paid (−30 min) |
|---|---|---|
| 9:00–5:00 | 8:00 | 7.5 hrs |
| 8:00–5:00 | 9:00 | 8.5 hrs |
| 8:00–4:00 | 8:00 | 7.5 hrs |
| 7:00–3:00 | 8:00 | 7.5 hrs |
| 9:00–5:30 | 8:30 | 8.0 hrs |
How many hours is 8 to 5?
From 8:00 a.m. to 5:00 p.m. is 9 hours of elapsed time. After a standard one-hour unpaid lunch that's 8 paid hours; with a 30-minute lunch it's 8.5.
What is 7.5 hours in hours and minutes?
7.5 hours is 7 hours and 30 minutes, because 0.5 of an hour is 30 minutes (0.5 × 60).
How many work hours are in a week, month and year?
A standard full-time schedule is 40 hours a week, which works out to about 173 hours in an average month and 2,080 hours in a year.
How do I add up hours and minutes on a time card?
Convert each day to decimal first (divide the minutes by 60), add the decimals, and you have your weekly total. Adding raw hours and minutes by hand is where mistakes creep in, so the calculator above does it for you.
What's the difference between part-time and full-time hours?
Full-time is generally 35–40 hours a week. Part-time is usually anything under about 30–35, though the exact line depends on your employer and benefits rules.