📅 Date & Time
Add Time Calculator
Time arithmetic is awkward because minutes and seconds roll over at 60, not 100. This calculator works in total seconds, so carrying is handled exactly — 1 h 45 min 30 s plus 2 h 20 min 45 s comes out as 4:06:15. The decimal-hours figure is what you need for a timesheet.
How it works
Hours (first duration)
Minutes (first duration)
Seconds (first duration)
Hours (second duration)
Minutes (second duration)
Seconds (second duration)
Operation
Result (HH:MM:SS)
Decimal hours
Total seconds
Hours
Minutes
Seconds
Frequently asked questions
How do I use the Add Time Calculator?
Fill in the fields above — the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.