How the hours calculator works
Hours worked in a day is the time between clocking in and clocking out, minus any unpaid break. The calculator converts each time to minutes since midnight, subtracts, removes the break, and reports the result both as h:mm (what a time clock prints) and as decimal hours (what payroll multiplies by your rate):
minutes worked = (end - start) - unpaid break decimal hours = minutes worked / 60
If the end time is earlier than the start time the shift is assumed to run overnight, so 10:00 PM to 6:00 AM is 8 hours.
Worked example
The form defaults describe a common schedule: 9:00 AM to 5:30 PM with a 30-minute unpaid lunch, Monday through Friday, at $20 an hour.
9:00 AM = 540 minutes since midnight 5:30 PM = 1,050 minutes 1,050 - 540 = 510 minutes, minus 30 = 480 minutes 480 / 60 = 8.00 hours per day (8:00) 5 days x 8.00 = 40.00 hours per week 40.00 x $20 = $800.00
Minutes to decimal hours
The step most people get wrong is treating 7:45 as 7.45 hours. Minutes are sixtieths, so 45 minutes is 0.75 hours. The table below covers the common quarter-hour and ten-minute marks; for anything else, divide the minutes by 60.
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
Using it as a time card calculator
Fill in only the days you worked; blank days are skipped. Each row can have its own break, so a short Friday with no lunch and a long Wednesday with an hour off both calculate correctly. The weekly total is the sum of the daily minutes, converted once at the end, which avoids the rounding drift you get from rounding each day to two decimals first. Enter an hourly rate to see gross pay for the week; leave it blank to see hours only.
Rounding rules employers use
US wage regulations allow rounding punches to the nearest 5, 6, or 15 minutes as long as the rounding is neutral over time. Under quarter-hour rounding, a 9:07 AM punch becomes 9:00 and a 5:23 PM punch becomes 5:30, so your time card may show slightly different hours than the exact figure here. If your pay stub consistently shows fewer hours than you clocked, compare the exact totals from this page to what the rounding produces.
To add or subtract durations rather than clock times, use the time calculator.