Frequency Converter

Frequency Converter handles the hertz family along with the rotational and angular units that measure the same thing differently. One hertz is one cycle per second, so 50 Hz mains electricity alternates fifty times a second.

Revolutions per minute is the same quantity divided by sixty: 3,000 rpm is 50 Hz, which is exactly why a two-pole motor on a 50 Hz supply runs at 3,000 rpm and the same motor on 60 Hz runs at 3,600. Beats per minute, used for music tempo and heart rate, converts identically.

Radians per second is the angular velocity form used in physics and control engineering, and it differs by a factor of 2π: one hertz is about 6.283 radians per second, because one full revolution is 2π radians. Mixing the two up puts a factor of 6.28 into a calculation, which is usually obvious and occasionally not.

The page shows its working, not just its answer. Where there is a formula it is printed with your own numbers substituted in, so you can check the result rather than take it on trust -- which is the difference between a calculator you can use for something that matters and one you cannot.

Everything runs inside your browser. What you type is never uploaded, never logged and never stored, and the calculator keeps working if your connection drops after the page has loaded.

• Shows result, to twelve digits, conversion factor, the other way and in scientific notation together, so you are not running it twice
• A results table you can read across
• Updates as you type, with no button to press and no page reload
• Copy the result in one click
• Free, no sign-up, and it runs entirely in your browser

The frequency converter is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Converting a motor speed between RPM and hertz
• Converting a processor or radio frequency between MHz and GHz
• Getting radians per second for an angular velocity calculation
• Converting a musical tempo into hertz