Convert H:M:S to Hours

What this converter does

This takes a time written as hours, minutes, and seconds and turns it into a single number of hours, decimals included. So 2 hours 30 minutes becomes 2.5 hours. It is the form you want when a time has to go into a sum, like a timesheet, a bill, or an average, where a tidy decimal is far easier to work with than three separate parts.

How to use it

1. Hours, Minutes, Seconds. Enter each part of the time.

Press Convert and it shows the total in decimal hours.

How the conversion works

Each part is turned into hours and added together. The hours count as themselves. The minutes are divided by 60, since there are 60 minutes in an hour. The seconds are divided by 3,600, since there are that many seconds in an hour. Add the three and you have the total in hours. So 30 minutes is 30 divided by 60, which is 0.5 of an hour, and 0 seconds adds nothing, giving 2.5 for 2 hours 30 minutes.

Why you would want decimal hours

The reason is almost always arithmetic. To work out pay or a bill you multiply an hourly rate by the hours, and you cannot cleanly multiply "2 hours 30 minutes," but you can multiply 2.5. The same goes for averaging several times or adding up a column of durations, where a single decimal in each row keeps the maths simple. So this is the step that turns a readable time into a calculable one.

An example

Take 1 hour, 15 minutes, and 30 seconds. The 15 minutes is 15 divided by 60, which is 0.25. The 30 seconds is 30 divided by 3,600, which is about 0.0083. Add them to the 1 hour and you get roughly 1.2583 hours. The tool carries it to four decimal places so the seconds are not lost in rounding.

Questions people ask

How do I convert H:M:S to decimal hours?

Divide the minutes by 60 and the seconds by 3,600, then add both to the hours. So 2 hours 30 minutes is 2 plus 0.5, which is 2.5.

What is 30 minutes in decimal hours?

0.5, because 30 divided by 60 is a half. Fifteen minutes is 0.25 and forty-five minutes is 0.75.

Does it count the seconds?

Yes. Seconds are divided by 3,600 and added in, and the result is shown to four decimal places so small amounts still register.

How do I go back to H:M:S?

Use an hours-to-H:M:S converter, which takes a decimal like 2.5 and turns it back into 2h 30m 0s.