Frequency Converter

By Suraj GiriUpdated 24 September 2026

This page converts a frequency from one unit into another. Every value passes through the hertz, the SI unit frequency is held in, and frequency stays frequency: a unit only converts inside its own dimension.

How do you convert a frequency between hertz and rpm?

Pick the unit you have, pick the unit you want, and type the value. The page multiplies by the factor between the two and prints the arithmetic under the result, so the answer and the working are the same object.

1. Choose the unit your value is in. This page opens on the revolution per minute.
2. Choose the unit you want it in. This page opens on the hertz.
3. Type the value, or the value with its units, such as 1500 rpm to Hz. The result and the factor behind it appear together.
4. Read the working. It converts into the hertz first and out again, which is the same two lines you would write by hand.

Hertz and rpm both measure how often something repeats, so for time, speed or any other quantity, start from the unit converter for every quantity.

Frequency Conversion Table

One row per unit this page offers, each measured against the hertz. The last column says whether the factor is a definition or a reading of one.

Worked Examples

The question the bank ranked highest for this page, answered with the working.

Where These Factors Come From

Every factor above is read from the knowledge base rather than typed for the page, and every result is worked from those factors. These are the statements it holds for frequency.

• One hertz is one cycle per second, so the hertz is the reciprocal second. One revolution per minute is 1/60 Hz, which means 1 Hz is 60 rpm.
• An SI prefix multiplies a unit by a power of ten: k is 10^3, M is 10^6, G is 10^9, m is 10^-3, micro is 10^-6 and n is 10^-9. The prefix belongs to the unit, so 1 kV is 1000 V.
• How this page reports a result result in the target frequency unit; rpm is treated as cycles per minute

SI prefixes on this page

Is a Cycle the Same as a Revolution?

For a rotating shaft a cycle and a revolution are the same event counted the same way, which is why revolutions per minute carries the dimension of a frequency. The hertz counts cycles per second and rpm counts them per minute, so the two differ by the minute alone.

• Revolutions per minute count per minute and hertz count per second, so reading an rpm figure as hertz is off by the minute.

The rule behind this factor is the same for every unit - how SI prefixes scale a unit.

Frequently Asked Questions

Related Conversions

• Time sits in the same measurement group as frequency - convert a duration between seconds, minutes and hours.
• If you are measuring angle rather than frequency, convert an angle between radians, degrees and turns instead.
• If you are measuring torque rather than frequency, convert torque between newton-metres and pound-force inches instead.
• If you are measuring voltage rather than frequency, convert a voltage between volts and kilovolts instead.
• If you are measuring speed rather than frequency, convert a speed between knots, mph and km/h instead.
• If you are measuring digital storage rather than frequency, convert digital storage between GB and GiB instead.

The rest of the family sits on the unit converter index.