Three calculators in one
- Add / subtract: total several entries such as 8h 30m + 7h 45m − 1h. Each row can be plus or minus, and seconds are optional. Handy for weekly timesheets or study logs.
- Between two times: enter a start and end time to get the elapsed time. If the end is earlier than the start, it is treated as crossing midnight, so night shifts just work. Enter a break in minutes to deduct it.
- Time + duration: add or subtract hours and minutes from a clock time — 22:30 plus 3h 45m is 02:15 the next day — with the day change shown.
Decimal hours vs hours and minutes
Payroll and timesheets often use decimal hours. Divide minutes by 60.
| Hours & minutes | Decimal hours |
|---|---|
| 15 min | 0.25 h |
| 30 min | 0.5 h |
| 45 min | 0.75 h |
| 1 h 45 min | 1.75 h |
| 7 h 30 min | 7.5 h |
| 8 h 20 min | about 8.33 h |
A common mistake is writing 1 h 20 min as 1.2 h — use the converter at the bottom to check.
Tips
Multiply your total by an hourly rate for a rough pay estimate; for Korean minimum wage and weekly holiday pay (주휴수당), see the Hourly Wage Calculator. For counting days (D-day, days between dates) use the Date Calculator. This tool only does time arithmetic — what counts as paid working time depends on your contract and local rules.