# Hour conversions

The hour conversion selector on this page selects the time measurement unit 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.

## About hour

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 3,601 seconds.

One hour (h) is also equal to 3,600 × 10^{3} 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 (h) 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