Communication Aids

Repeater Offset Calculator

Compute the transmit frequency from an output frequency using standard band-plan offsets.

01

Tool

Band plan2 m: −600 kHz
Applied offset-0.6 MHz
Your TX frequency146.340 MHz
02

How it works

FM repeaters listen on one frequency and transmit on another. Standard offsets in the ARRL/IARU R2 band plan are: 29 MHz −100 kHz, 52 MHz −500 kHz or −1 MHz, 146 MHz ±600 kHz, 222 MHz −1.6 MHz, 440 MHz +5 MHz, 902 MHz −25 MHz. The correct sign depends on where in the band the output sits.

03

How to use

  1. Enter the repeater output frequency (MHz).
  2. The tool picks the standard offset for that band and shows your TX frequency.
  3. Override the offset manually if your local band plan differs.
04

Frequently asked questions

What about CTCSS/DCS tones?

Offset gets you on frequency, but most repeaters also require an access tone. Check your local repeater directory.

Why is 70 cm sometimes +5 and sometimes −5?

It depends on where the output frequency sits within the sub-band. The tool applies the common ARRL convention.