Hours Calculator
Add and subtract hours and minutes, line by line
Type each duration as 1:30 or as 1.5 and choose whether it adds to the total or comes off it. The running total is shown after every line, so you can see where a figure went wrong without starting again.
Use the plus and minus button on the left of a line to switch it between adding and subtracting.
How this hours calculator works
Time is not decimal, which is why adding it on a normal calculator goes wrong. 7:45 plus 6:30 is not 13.75 or 14.15 - it is 14:15, because the minutes carry at sixty, not at a hundred. This page converts every line to whole minutes first, adds or subtracts them, and converts back only for display.
Minutes for a line = hours x 60 + minutes
Total = the added lines' minutes - the subtracted lines' minutes
Displayed time = total / 60 hours and total mod 60 minutes
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Each line can be typed as hh:mm (2:20) or as decimal hours (2.33) - both are accepted, and you can mix them in one list.
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The running total on the right of each line is the total up to and including that line.
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Totals never wrap at 24 hours, so a working week shows as 41:15 rather than 17:15.
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Subtracting more than you have added gives a negative total, which is exactly what a flexitime balance needs.
Worked example
Two work blocks and a long lunch that came out of the middle of the second one:
+ 7:45 = 465 minutes (running total 7:45)
+ 6:30 = 390 minutes (running total 14:15)
- 1:15 = 75 minutes (running total 13:00)
Total 780 minutes = 13:00 = 13.00 decimal hours
The same list on a pocket calculator, typed as 7.45 + 6.30 - 1.15, gives 12.60 - nearly half an hour adrift, and adrift in the direction that costs you money.
When a running total earns its keep
A single grand total tells you the answer is wrong but not where. The running total column tells you which line broke it: scan down until the number stops matching your expectation and the mistake is on that line. It is the same reason a bank statement shows a balance after every transaction rather than only at the bottom.
Stop retyping your hours
Adding up durations by hand means you first had to write them down. TickTappy times the work as it happens, so the durations are already there and already added up. Free, no account needed.
FAQ
How do I add hours and minutes together?
Convert each time to minutes, add the minutes, then convert back. 7:45 is 465 minutes and 6:30 is 390 minutes, so together they are 855 minutes, which is 14:15. Adding 7.45 and 6.30 as if they were decimals gives 13.75, which is wrong by half an hour.
Can the total be negative?
Yes. If you subtract more time than you have added, the total is shown with a minus sign, for example -1:30. That is useful for flexitime balances, where the question is how far ahead or behind you are.
Can I add up more than 24 hours?
Yes. Totals do not wrap at midnight, so 40 hours shows as 40:00 rather than 16:00. Individual lines can be longer than a day too, so 100:30 is a valid entry.
Can I type decimal hours instead?
Yes, and you can mix the two. 1.5 and 1:30 are both read as ninety minutes, and 1,5 works too for the comma-decimal habit. Whatever you type, the total is shown in both formats.
Is anything saved between visits?
No. The lines exist only while the page is open. Nothing is uploaded and nothing is stored, so reloading brings back the three example lines.
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