Convert H:M:S to Seconds

What this converter does

This turns a duration written as HH:MM:SS into a single total number of seconds. So 01:30:00 becomes 5,400 seconds. Seconds are the unit a lot of technical work runs on, so this is the one to reach for when you are dealing with code, video and audio timings, log durations, or anything where the base unit needs to be plain seconds.

How to use it

1. Duration. Type the time in HH:MM:SS form, such as 01:30:00.

Press Convert and it shows the total in seconds.

How the conversion works

It splits your duration at the colons into hours, minutes, and seconds, then brings each down to seconds and adds them. The hours are multiplied by 3,600, the number of seconds in an hour. The minutes are multiplied by 60. The seconds are added as they are. The sum is the whole duration in seconds. It is a small, exact piece of arithmetic with no rounding to worry about, since seconds are the smallest unit here.

Why seconds are the unit code likes

Seconds turn up everywhere in technical settings because they are a single, whole, easily handled unit. Programming often measures durations and timeouts in seconds, video and audio editing tracks position in seconds, and many logs and systems record elapsed time the same way. Reducing a HH:MM:SS duration to one number of seconds is usually the first step before you can feed it into a script, a config, or a calculation, which is why this conversion comes up so often in that kind of work.

An example

Take 01:30:00. The 1 hour is 3,600 seconds and the 30 minutes is 1,800 seconds, which add up to 5,400 seconds, with no seconds left on the end. A shorter one: 00:02:30 is 120 seconds for the 2 minutes plus 30, giving 150 seconds.

Questions people ask

How do I convert H:M:S to seconds?

Multiply the hours by 3,600, the minutes by 60, and add those to the seconds. So 01:30:00 is 3,600 plus 1,800, which is 5,400 seconds.

What format should I type the time in?

Use HH:MM:SS with colons, like 01:30:00. The tool reads the three parts from that and adds them up.

How many seconds is one hour?

3,600 seconds, which is 60 minutes times 60 seconds. Two hours is 7,200, and so on.

How do I turn seconds back into H:M:S?

Use a seconds-to-H:M:S converter, which takes a number of seconds and lays it out as hours, minutes, and seconds.