Time Calculator (Totals & Time Difference)
＋More features: time-card calculation and decimal-to-h:mm conversion
Time-card calculation (hours worked and that day’s pay)
If the clock-out time is earlier than the clock-in time, it is treated as an overnight shift. Enter an hourly wage to also get a rough figure for that day’s pay.
Convert decimal hours back to “h:mm”
Check what the “7.75 hours” on a pay slip or in Excel means in hours and minutes.
Add up times like 1:30 + 0:45, or get the elapsed time from a start to an end time, instantly. The decimal notation commonly used on Japanese pay slips (7.75 hours and so on) is shown at the same time — handy for totalling your working hours or part-time shifts.
How to use
- Choose “Add up times” or “Time difference”.
- For a total, enter “h:mm” one per line (or comma-separated); for a difference, pick the start and end times.
- The total and its decimal conversion appear automatically as you type (pressing the button works too).
How it is calculated
- Everything is converted to minutes first (1:30 → 90 minutes).
- Decimal hours = total minutes ÷ 60 (e.g. 8 hours 30 minutes = 510 minutes ÷ 60 = 8.5 hours)
- If the end time is earlier than the start time, 24 hours are added, treating it as a shift that crosses midnight (a night shift, for example).
Sources and assumptions
- This is arithmetic based on the unit conversion 1 hour = 60 minutes.
Assumptions and notes
- The time difference does not subtract breaks. When calculating working hours, subtract break time separately.
- Payroll rounding rules (such as truncating to 15-minute units) depend on your employer.
Frequently asked questions
Isn’t 8 hours 30 minutes “8.3 hours”?
No. 30 minutes is 0.5 hours, so it is 8.5 hours. Mixing up the “h:mm” and decimal notations is a common payroll mistake, which is why this tool shows both side by side.
How do I get the hours actually worked after a 1-hour break?
Get the total time with “Time difference” first, then subtract 1 hour from the displayed total (a negative entry such as “-1:00” cannot be typed into the list). Example: 9:00–18:00 = 9 hours → 8 hours worked.
Can I use this to total a month of overtime?
Yes. Paste your daily overtime (0:45 and so on) separated by line breaks, and you get the monthly total together with its decimal conversion (the format often used on pay slips) in one go.