Revolutions per hour is the number of turns in one minute. It is a unit of rotational speed. It is also used in frequency of rotation around a fixed axis. According to the International System of Units (SI), rpm is not a unit. This is because the word revolution is a semantic annotation rather than a unit. On many kinds of disc recording media, the rotational speed of the medium under the read head is a standard given in rpm
| Standard Units | |
|---|---|
| Cycle/second | {{cyclepersecond}} |
| Degree/hour | {{degreeperhour}} |
| Degree/minute | {{degreeperminute}} |
| Degree/second | {{degreepersecond}} |
| Gigahertz | {{gigahertz}} |
| Hertz | {{hertz}} |
| Kilohertz | {{kilohertz}} |
| Megahertz | {{megahertz}} |
| Millihertz | {{millihertz}} |
| Radian/hour | {{radianperhour}} |
| Radian/minute | {{radianperminute}} |
| Radian/second | {{radianpersecond}} |
| Revolution/hour | {{revolutionperhour}} |
| Revolution/second | {{revolutionpersecond}} |
| RPM | {{rpm}} |
| Terrahertz | {{terrahertz}} |