How do you convert kHz to MHz?

Divide by 1,000: MHz = kHz / 1,000. A station at 1,000 kHz on the AM dial is broadcasting at 1 MHz.

What frequency range does AM radio use?

AM radio broadcasts in the range of roughly 530 to 1,700 kHz — equivalent to about 0.53 to 1.7 MHz, a much narrower-looking range once expressed in MHz, which is one reason AM tuning dials traditionally show kHz.

What frequency range does FM radio use?

FM radio broadcasts in the range of roughly 88 to 108 MHz — equivalent to 88,000 to 108,000 kHz, a number large enough that MHz is the more practical display unit.

Why doesn't AM radio just use MHz like FM does?

Convention, largely: AM's frequency range sits in the hundreds-of-kHz to low-MHz range, and kHz keeps AM dial numbers in a familiar few-digit format that predates FM broadcasting and has stuck ever since, even though nothing prevents expressing an AM frequency in MHz.

Guide

kHz vs MHz: why AM and FM radio use different scales

A kilohertz is 1,000 Hz; a megahertz is 1,000,000 Hz — exactly 1,000 times larger. AM radio's 530–1,700 kHz band and FM's 88–108 MHz band sit in genuinely different parts of the spectrum, not just different display units.

By Buğra SözeriPublished September 25, 2026

Kilohertz and megahertz are both just decimal multiples of the hertz, the SI unit of frequency — a kilohertz is 1,000 Hz, a megahertz is 1,000,000 Hz. The reason AM and FM radio ended up on different scales isn't arbitrary labeling: the two broadcast bands genuinely occupy different, far-apart regions of the radio spectrum, and each unit happens to produce more readable numbers for its own band.

The exact conversion

MHz = kHz / 1,000
kHz = MHz × 1,000

AM vs FM band ranges

Band	Range in kHz	Range in MHz
AM radio	530–1,700 kHz	0.53–1.7 MHz
FM radio	88,000–108,000 kHz	88–108 MHz

The gap is stark: FM's lowest frequency (88 MHz) is still more than 50 times higher than AM's highest frequency (1.7 MHz). That physical separation — not just a labeling choice — is why AM and FM behave so differently in practice, including AM's longer range via ground-wave and nighttime skywave propagation versus FM's shorter, more line-of-sight reach.

Reading a frequency spec at a glance

A quick rule of thumb: if a broadcast or signal frequency is quoted with three or four digits and no decimal (like 1010 or 680), it's almost certainly in kHz and likely AM radio or a similar mid-range signal. If it's quoted with two or three digits and a decimal point (like 101.5 or 88.1), it's virtually always MHz — FM radio, VHF, or a similar band. This pattern-matching shortcut works because broadcast engineers chose each unit specifically to keep dial numbers in a readable, low-digit-count range for that band.

Frequently asked questions

How do you convert kHz to MHz?: Divide by 1,000: MHz = kHz / 1,000. A station at 1,000 kHz on the AM dial is broadcasting at 1 MHz.
What frequency range does AM radio use?: AM radio broadcasts in the range of roughly 530 to 1,700 kHz — equivalent to about 0.53 to 1.7 MHz, a much narrower-looking range once expressed in MHz, which is one reason AM tuning dials traditionally show kHz.
What frequency range does FM radio use?: FM radio broadcasts in the range of roughly 88 to 108 MHz — equivalent to 88,000 to 108,000 kHz, a number large enough that MHz is the more practical display unit.
Why doesn't AM radio just use MHz like FM does?: Convention, largely: AM's frequency range sits in the hundreds-of-kHz to low-MHz range, and kHz keeps AM dial numbers in a familiar few-digit format that predates FM broadcasting and has stuck ever since, even though nothing prevents expressing an AM frequency in MHz.

Sources & references

Authoritative references cited by this piece. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.

BIPM — SI Brochure, 9th edition (hertz and its decimal multiples kHz/MHz/GHz) — Reference for how kilohertz and megahertz relate to the base hertz unit(as of 2026-09-25)