Hour (h) Conversions
An hour is a unit of time equal to one twenty-fourth of a day. Each hour contains 60 minutes or 3,600 seconds.
1 h = 60 min = 3,600 s
What Is an Hour?
We use hours to measure parts of a day and describe times and durations. A school lesson might last one hour, a journey might take three hours, and an appointment might begin at a particular hour of the day.
A complete 24-hour day contains:
- 24 hours
- 1,440 minutes
- 86,400 seconds
The Word “Hour”
The English word hour has a long history. It came into Middle English through Anglo-French and can be traced to the Latin word hora and the Greek word hōra. Merriam-Webster records its first known English use in the 13th century.
Today, “hour” can mean a period of 60 minutes, a particular time of day, a working period, or even the time needed to travel somewhere.
How to Convert Hours
To convert hours to another fixed time unit, use seconds as the common reference:
Target value = hours × 3,600 ÷ seconds in the target unit
Example: Convert 2.5 hours to minutes
Each hour contains 60 minutes:
2.5 h × 60 min/h = 150 min
Example: Convert 3 hours to seconds
Each hour contains 3,600 seconds:
3 h × 3,600 s/h = 10,800 s
Common Hour Conversions
- 1 h = 60 min
- 1 h = 3,600 s
- 1 h = 3,600,000 ms
- 1 h = 1/24 day ≈ 0.0416667 day
- 1 h = 1/168 week ≈ 0.00595238 week
Conversions involving months or years are usually approximate because calendar months and years do not all have the same length.
Hours on 12-Hour and 24-Hour Clocks
A 12-hour clock divides the day into two periods and uses a.m. and p.m. A 24-hour clock counts continuously from 00:00 to 23:59.
For example, 4:30 p.m. on a 12-hour clock is written as 16:30 on a 24-hour clock. This changes how the time is written, but it does not change the length of an hour.
Hour Conversion Links to Other Time Units
Convert hours (h) to another supported time unit: