How this calculator works
The hour is defined as 60 minutes, and the minute as 60 seconds, so an hour is exactly 3,600 seconds. The second is the SI base unit of time, defined from the caesium-133 transition, so every larger unit is a fixed multiple of it. Multiplying hours by 3,600 gives seconds and dividing seconds by 3,600 gives hours. This page uses the ordinary fixed hour and ignores leap seconds, which are occasional one-second adjustments to UTC.
Formula
seconds = hours x 3,600. hours = seconds / 3,600. 1 h = 60 min = 3,600 s.
Worked example
2 h is 7,200 s. A 90-minute film is 1.5 h, or 5,400 s. A 24 h day is 86,400 s. Half an hour is 1,800 s, and 10,000 s is 2.77778 h.
Advertisement
Frequently asked questions
How many seconds are in an hour?
Exactly 3,600, because an hour has 60 minutes and each minute has 60 seconds, and 60 x 60 = 3,600.
How do I convert hours, minutes and seconds together?
Multiply the hours by 3,600, the minutes by 60, add the seconds, then add all three. For 1 h 30 min 15 s the total is 3,600 + 1,800 + 15 = 5,415 s.
Why does a battery rating use seconds?
Energy and charge ratings are usually in watt-hours or amp-hours, but timers, countdowns and log files store elapsed time in seconds. Converting to seconds makes durations easy to add.
Does a leap second change the answer?
Only for real clock time. This page uses the ordinary 3,600-second hour. A leap second adds one second to UTC occasionally, so a precise count of elapsed real time can differ by a second.