Revolutions Per Minute to Megahertz (rpm to MHz)

1 revolution per minute equals 1.666666667×10⁻⁸ megahertz (rounded).

How to convert revolutions per minute to megahertz

To convert revolutions per minute to megahertz, multiply the number of revolutions per minute by 1.666666667×10⁻⁸. The factor is rounded to 10 significant digits. To go the other way, multiply megahertz by 60,000,000.

megahertz = revolutions per minute × 1.666666667×10⁻⁸

Example: 10 revolutions per minute = 1.666666667×10⁻⁷ megahertz.

About these units

Revolution Per Minute (rpm)

Metric (SI)Current unit

One 60th of a hertz. The unit for engine, motor and turntable speeds.

Records gave rpm its fame. The 78 rpm speed was not chosen for a clear engineering reason; Wikipedia says it apparently happened to be the speed of one of the early machines, and the Gramophone Company formally set it as a recording standard in 1912. Columbia unveiled the 33 and a third rpm LP on 21 June 1948, and RCA Victor released the 45 rpm single in February 1949, starting a period called the War of the Speeds.

One rpm equals one sixtieth of a hertz, so a disc at 60 rpm turns at 1 Hz. The SI does not recognise rpm as a unit, preferring hertz or radians per second, and r/min is the usual symbol in standards. Typical examples are a modern car engine idling at about 750 to 900 rpm, consumer hard drives at 7,500 to 10,000 rpm, power-generation turbines at 3,000 or 3,600 rpm, and uranium centrifuges of the Zippe type at 100,000 rpm or more.

1 revolution per minute = 0.01666666667 hertz (approximately).

Sources: Wikipedia: Revolutions per minute; Wikipedia: Phonograph record

Megahertz (MHz)

Metric (SI)Current unit

One million hertz. FM radio and older processors.

Engineers once said megacycles, and the older unit shows up in postwar papers, one 1946 study on ultrasound in liquids being titled with 15 megacycles. When hertz replaced cycles per second, the megacycle per second, Mc/s, became the megahertz. The word then entered home computing: Wikipedia notes personal computer clock speeds of around 1 MHz in the late 1970s on machines from Atari, Commodore and Apple.

A megahertz is one million hertz, the natural scale of broadcast radio. FM stations in most of the world use 87.5 to 108 MHz, with the Americas using 88 to 108 MHz and Japan using 76 to 95 MHz. In North America channels are spaced 200 kHz apart, and the FCC reassigned FM to its present band in 1945. As a way to rate computers, clock speed is criticised by many experts, who call it an easily manipulable benchmark because some chips need several cycles per operation and others perform several operations in one.

1 megahertz = 1,000,000 hertz (exactly).

Sources: Wikipedia: Megahertz; Wikipedia: FM broadcast band

Related conversions

See all frequency units.