What is the Time Card Hours Calculator?
The Time Card Hours Calculator works out how long you worked between a start time and an end time, just like adding up a paper time card or time sheet. Enter when you clocked in and out, optionally deduct an unpaid break, and the tool returns your total in three handy formats: hh:mm, decimal hours (useful for payroll), and total minutes.
How to use it
Choose a 12-hour or 24-hour clock. Type your times without a colon: 915 means 9:15 and 1225 means 12:25. A one or two digit entry is treated as a whole hour (for example 9 = 9:00). In 12-hour mode, set the am/pm dropdown for each time. Finally, enter any break in minutes to subtract it from the total. The calculator also handles overnight shifts that pass through midnight.
The formula explained
Each time is converted to minutes since midnight. The raw span is End minutes minus Start minutes. If that is negative the shift crossed midnight, so 1440 minutes (24 hours) is added. The break is then subtracted to give net minutes, which is split into hours and remaining minutes for the hh:mm display and divided by 60 for decimal hours.
$$\text{Net Minutes} = (\text{End} - \text{Start}) - \text{Break}$$$$\text{Span} = \text{End}_{min} - \text{Start}_{min} \;(+1440\text{ if negative})$$$$\text{Hours} = \dfrac{\text{Span} - \text{Break}}{60}$$
Worked example
Start 9:00 am, end 5:00 pm, 30 minute break. Start = 540 minutes, end = 1020 minutes, raw span = 480 minutes (8 hours). Subtract the 30 minute break to get 450 net minutes, which is 07:30, 7.50 hours, or 450 minutes.
$$\text{Span} = 1020 - 540 = 480 \text{ minutes}$$$$\text{Net Minutes} = 480 - 30 = 450 \text{ minutes}$$$$\text{Hours} = \dfrac{450}{60} = 7.50$$
FAQ
How do I enter midnight and noon? 12:00 am is midnight (00:00) and 12:00 pm is noon (12:00).
Does it handle overnight shifts? Yes. If the end time is earlier than the start time, the calculator assumes the shift ran past midnight and adds a full day.
What if my break is longer than the shift? The net time is clamped to zero, since you cannot deduct more break than time actually worked.
