SDR center frequency calculator

This calculator will help you determine the center frequency for your radios based on the frequencies you want to monitor. It is useful for configuring SDRs to monitor digital trunked systems.

You can also use URL query parameters to pre-fill the calculator. Use freqs to specify the frequencies and rate to specify the sample rate (example).


You can paste the site frequencies directly copied from Radio Reference. The calculator will clean-up the text automatically.
When setting the sample rate for your SDR, ensure it does not exceed your device's maximum capability. If the frequency range you need to cover is larger than your radio's sample rate, use multiple radios to distribute the load. A higher sample rate allows monitoring of a broader frequency range but requires more computational power, consider more radios with a smaller sample rate.