Radio bitrates, bandwidth and listener limits

Bandwidth is the real constraint on a radio station. The maths is simple and worth doing before you advertise.

The formula

bandwidth = bitrate × concurrent listeners

At 128 kbps:

Picking a bitrate

• 128 kbps MP3/AAC — excellent for music; the sweet spot.

• 64 kbps — fine for talk radio; reaches far more people on mobile data.

• 256 kbps — marginal quality gain for double the bandwidth; rarely worth it for streaming.

Lower bitrate = same server serves roughly twice as many listeners. For a talk station, 64 kbps is not a compromise — it is correct.

Codec matters

AAC generally sounds better than MP3 at the same bitrate. Some older players prefer MP3. Many stations offer both mounts and let listeners pick.

Listener limits and overage

Set a realistic listener cap. If you exceed it, either extra listeners are refused (better than degrading everyone) or you incur overage. Monitor concurrent listeners over time and resize before your peak doubles.

How many listeners do I actually need?

Be honest about your audience. Most new stations have tens, not thousands, of concurrent listeners at launch; it is concurrency that costs bandwidth, not total unique listeners. A spike during a live event is the usual reason to raise the cap.

Reducing cost without hurting listeners

• Serve a lower bitrate for mobile (many streamers support multiple mounts).

• Use a CDN for popular streams so most listeners are served from edge nodes rather than your origin.

• Cap bits per listener rather than listener count if your provider bills that way.

Related reading

• Monitoring your bandwidth

• Radio hosting setup