Time Duration Calculator
Adds and subtracts hh:mm:ss durations, totals a column of times and converts to decimal hours.
Add up a column of hh:mm:ss durations, or work out hours from a list of shifts with breaks taken off. The shift mode also splits regular from overtime and marks the night hours, which is what a timesheet argument is usually about.
What are you adding up
Durations
One per line. 1:30, 90m, 1h 30m and 1.5 are all ninety minutes here.
Total
total
06:35:00
in hours
6.58
compact
6h 35m
average
01:19:00
entries counted
5
skipped
0
How to use it
Choose what you are adding up
A column of durations, or a list of shifts written as start-end. The second understands breaks and midnight crossings; the first is plain addition.
Paste the lines
One per line, in whatever shape you have: 1:30, 90m, 1h 30m and 1.5 are all ninety minutes. For shifts, 09:00-18:00 -60 takes an hour of break off.
Say what a bare number means
A line that just says 1.5 could be an hour and a half or a minute and a half. Choose once and every such line is read the same way.
Common questions
Why does my spreadsheet total differ?
A spreadsheet cell formatted as time wraps at 24 hours unless the format is in brackets, so 30 hours shows as 6:00. Nothing here wraps: a total of 30 hours is shown as 30 hours.
How is a night shift handled?
A shift ending earlier than it starts is read as running past midnight, so 22:00-06:00 is eight hours rather than minus fourteen.
Are the overtime multipliers legally right?
They are the ordinary Korean statutory rates — 1.5× for overtime, an extra 0.5× for hours between 22:00 and 06:00 — and they are a calculation, not advice. Contracts, allowances and the 5-employee threshold all change the real figure.
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