Hertz to gigahertz: reading the microwave bands
What this conversion does
It divides by a billion, turning a long integer into the short decimal that engineers use when they talk about microwave links. Wi-Fi channel 1 is 2,412,000,000 Hz and 2.412 GHz; the same signal, but only the second form is short enough to say out loud. Because the divisor is a power of ten, the conversion is exact and reversible.
Why gigahertz took over the datasheets
Above about one gigahertz the hertz figures become unwieldy: a single band spans hundreds of millions, and two adjacent channels differ by five million. Quoting those numbers in gigahertz, where the same channel spacing is 0.005 GHz, makes them comparable at a glance. The unit did not change what is being measured, only how many digits you have to read before you know which channel you are on.
Hertz to gigahertz conversion table
Everyday microwave frequencies with their hertz equivalents, including the three Wi-Fi channels that account for most of the traffic.
| Hertz (Hz) | Gigahertz (GHz) |
|---|---|
| 1 | 1e-9 |
| 50 | 5e-8 |
| 60 | 6e-8 |
| 440 | 4.4e-7 |
| 1000 | 0.000001 |
| 20000 | 0.00002 |
| 100000 | 0.0001 |
The same signal, four notations
A single Wi-Fi carrier can be written as 2412000000 Hz, 2412000 kHz, 2412 MHz or 2.412 GHz. All four are correct, and each is the right choice in a different document: a spectrum analyser reading, a channel plan, a router specification and a marketing page. Converting between them by hand is where a stray zero turns channel 1 into a frequency that does not exist.
Group the digits before you start
Write the hertz value in groups of three from the right. The first group is hertz, the second kilohertz, the third megahertz and the fourth gigahertz, so the leftmost group plus the remainder is your answer without any counting.
Frequently asked questions
How do I convert hertz to gigahertz?
Divide by one billion, or move the decimal point nine places to the left. Wi-Fi channel 1 at 2,412,000,000 Hz therefore becomes 2.412 GHz. The tool accepts the digits with or without grouping, and ignores spaces.
How many hertz is 2.4 GHz?
Exactly 2,400,000,000 Hz. The rounded name 2.4 GHz is a band label, though: the channel inside it usually sits at 2412, 2437 or 2462 MHz, so the exact figure is never quite the round one the name suggests.
Why is a gigahertz a billion hertz and not a million?
Because the SI prefixes step by a thousand each time. Hertz to kilohertz is a thousand, kilohertz to megahertz another thousand, and megahertz to gigahertz a third, so the total factor from hertz is a thousand cubed, which is a billion.
Can the converter handle a frequency above a billion hertz?
Yes, and comfortably. Values in the tens of billions of hertz — 24 GHz radar, for instance — convert without losing a digit, and results that would otherwise be very long are written in exponent form so that no significant figure is dropped.
What everyday devices run at gigahertz frequencies?
Wi-Fi and Bluetooth both occupy the 2.4 GHz band, satellite navigation broadcasts near 1.575 GHz, and a microwave oven agitates water at 2.45 GHz. Every one of them runs at billions of cycles per second, which is the scale the prefix exists to keep readable.