Hz to GHz: Wi-Fi and Bluetooth Channel Centre Frequencies

Reading Channel Centres Off a Regulatory Table

Spectrum allocations are published in whole hertz. A national frequency plan, a chipset register map or a certification report will happily print 5 955 000 000 where the sticker on the access point says "6 GHz". When you are choosing channels for a deployment, those nine-digit figures have to become the short band labels that survey tools, client radios and floor plans use — while staying exact enough to check against a band edge.

Conversion factor: divide hertz by 1 000 000 000. The centre of 2.4 GHz channel 6 is listed as 2 437 000 000 Hz, and 2 437 000 000 ÷ 1 000 000 000 = 2.437 GHz — the number a spectrum analyser marker or a survey report will show.

What the band label hides

A centre is only the middle of the occupied span

The published figure marks the middle of the channel, not its extent. A 20 MHz channel reaches 10 MHz either side, and an 80 or 160 MHz channel reaches four or eight times as far — which is where overlap and band-edge problems begin.

Band edges are hard numbers, not rounded ones

Emission limits are written against exact boundaries such as 7 125 000 000 Hz. Rounding a centre to two decimal places before you add half a channel width is how a plan ends up nominally legal and practically over the line.

Two standards share the same 2.4 GHz metres

Bluetooth Low Energy places its advertising channels deliberately around the Wi-Fi channel plan, so seeing both sets of centres in one unit is the fastest way to explain why a beacon estate and a wireless network coexist as well or as badly as they do.

Turning a Published Channel List Into GHz Labels

Paste the centre exactly as published

Long figures can be dropped in with their spacing intact — spaces are ignored and a comma is read as a decimal point, so a value copied out of a European document needs no cleaning up.

Read the band label, then add half the width

The gigahertz result tells you which allocation the channel sits in. To test whether it fits, work half the channel width outwards from the centre and compare both skirts against the edges of the allocation.

Switch a side to MHz when the source uses it

Plenty of channel tables are written in megahertz instead. Type into the searchable unit list on either side to move that side to MHz without losing the value you already entered.

Reverse it when you only know the label

Given a channel described as 5.745 GHz, the swap control hands back 5 745 000 000 Hz for a configuration file or a test-equipment centre-frequency entry.

Very small results flip format: anything below 0.000001 is printed in scientific notation, so a single-digit hertz entry appears as 1.000000e-9 rather than a row of zeros. Real channel centres are billions of hertz and always read as ordinary decimals.

Wi-Fi and Bluetooth Channel Centres Side by Side

Every figure below is the published centre of a channel, shown first as the regulator writes it and then as a radio planner would say it out loud. The 2.4 GHz rows are deliberately interleaved so the Bluetooth placement makes sense.

Channel	Centre in hertz	Centre in gigahertz	Where it sits
BLE advertising 37	2 402 000 000 Hz	2.402 GHz	Bottom of the 2.4 GHz band, in the lower skirt of Wi-Fi channel 1
Wi-Fi 2.4 GHz ch 1	2 412 000 000 Hz	2.412 GHz	Occupies roughly 2.402–2.422 GHz at 20 MHz wide
BLE advertising 38	2 426 000 000 Hz	2.426 GHz	In the narrow gap between Wi-Fi channels 1 and 6
Wi-Fi 2.4 GHz ch 6	2 437 000 000 Hz	2.437 GHz	25 MHz above channel 1, the middle of the three-channel plan
Wi-Fi 2.4 GHz ch 11	2 462 000 000 Hz	2.462 GHz	Top of the non-overlapping set in most regulatory domains
BLE advertising 39	2 480 000 000 Hz	2.48 GHz	Above channel 11's upper skirt, near the top of the band
Wi-Fi 5 GHz ch 36	5 180 000 000 Hz	5.18 GHz	First 20 MHz channel of the low 5 GHz allocation
Wi-Fi 5 GHz ch 149	5 745 000 000 Hz	5.745 GHz	Upper 5 GHz group, commonly free of radar-sharing rules
Wi-Fi 6 GHz ch 1	5 955 000 000 Hz	5.955 GHz	Lowest 20 MHz channel of the 6 GHz allocation
Wi-Fi 6 GHz ch 233	7 115 000 000 Hz	7.115 GHz	Highest 20 MHz channel; its upper skirt lands exactly on 7.125 GHz

Ten-digit centres survive intact

A 6 GHz centre is a ten-digit number and the last three digits are the ones that decide a band-edge argument. Values are carried through without being truncated to a friendly two-decimal label.

Megahertz tables handled on either side

Channel plans switch between hertz and megahertz depending on who published them. Searching the unit list on one side re-bases that column without retyping the frequency.

Beacon and network channels in one place

Because both sets of centres convert the same way, a Bluetooth advertising frequency and a Wi-Fi channel can be lined up directly when you are explaining an interference complaint.

Questions That Come Up During Wireless Planning

Does the centre frequency tell me how much spectrum a channel uses?

No — the centre and the width are separate specifications. A channel published at 5.18 GHz occupies 5.17–5.19 GHz at 20 MHz wide and 5.16–5.20 GHz once bonded to 40 MHz. Push the same centre to 160 MHz and it would demand 5.10–5.26 GHz, which is exactly why no 160 MHz channel is anchored there: the bottom of the allocation is in the way. The centre stays put while the skirts move outwards, so bonding decisions have to be checked against the edges every time.

Why are only three 2.4 GHz channels considered non-overlapping?

Adjacent channel numbers in that band are spaced 5 MHz apart, but each carrier is about 20 MHz wide, so neighbouring numbers sit almost on top of one another. Channels 1, 6 and 11 are 25 MHz apart in centre frequency — 2.412, 2.437 and 2.462 GHz — which is just enough separation for their occupied spans to stay clear. Everything in between is a compromise that spreads energy across two of the three usable slots.

Where does the 6 GHz allocation begin and end?

Where it is opened in full it runs from 5.925 GHz to 7.125 GHz — 1 200 MHz of contiguous spectrum, more than the 2.4 and 5 GHz bands combined. The lowest 20 MHz channel is centred at 5.955 GHz and the highest at 7.115 GHz, whose upper skirt lands precisely on the top boundary. Several regulators have released only the lower portion, so confirm the ceiling that applies where the equipment will be installed.

How are the three Bluetooth advertising channels spaced?

Bluetooth Low Energy divides the band into forty 2 MHz slots. Three of them carry advertising traffic and sit at 2.402, 2.426 and 2.48 GHz. Those positions are not evenly spread: they were picked to fall in the quiet spaces around the 1 / 6 / 11 arrangement, so a device broadcasting on all three has a good chance of at least one advertisement landing outside the busiest Wi-Fi carrier in the room.

Why do compliance documents print full hertz instead of a short GHz figure?

Because the limits they enforce are defined at exact boundaries, and a rounded label cannot be tested against one. "About 7.12 GHz" is not a statement anyone can measure a transmitter against, whereas 7 115 000 000 Hz plus a stated occupied bandwidth is. The same reasoning applies to the emission masks and guard distances quoted at the ends of every allocation, which is why plans are written in hertz and only spoken in gigahertz.