# Hour conversions

time conversions » hour conversionsThe online converter calculator on this page allows you to select the time measurement unit you want to convert to starting from hours (h). To make a conversion starting from a unit of time other than hour, simply click on the "Reset" button.

## What is hour?

### Definition:

The hour is a unit of time equal to 3,600 seconds (1 h = 3,600 s), the base unit of time in the International System of Units (SI). At irregular intervals, the Coordinated Universal Time (UTC) time scale is adjusted with leap seconds in order to keep the UTC time scale close to mean solar time. On these occasions, one hour has 3,599 or 3,601seconds.

One hour is also equal to 3,600x103 milliseconds (ms) (an SI unit of time), or 60 minutes (min) or 1/24 days (d), which are non-SI units of time but accepted for use along with other SI units.

- One hour is equal to 60 minutes
- A half of an hour (half-hour) is equal to 30 minutes
- A quarter of an hour (quarter-hour) is equal to 15 minutes

The hours are commonly used throughout the world for timekeeping. Times of this magnitude (i.e., on the hour time scale) can be measured by using a clock.

### Symbol:

h

### Plural:

hours

### Also known as:

stound

Below you can find a comprehensive list with conversions from hours to other (metric, imperial, or customary) time measurement units.