Audio Bitrate Explained: What It Means and How to Choose

Audio bitrate is the number of bits processed per second of audio. It directly controls the tradeoff between file size and sound quality. Higher bitrate means better audio but larger files. Lower bitrate means smaller files but more audible compression artifacts.

Common Bitrate Values

• 64 kbps - Acceptable for speech and talk radio. Noticeable quality loss on music.
• 128 kbps - Good quality for casual listening. The standard for most streaming services on mobile.
• 192 kbps - Near-transparent quality. Most people cannot tell the difference from the original.
• 320 kbps - Maximum MP3 bitrate. Virtually indistinguishable from uncompressed audio.

How Bitrate Affects File Size

A 3-minute song at 128 kbps is roughly 2.8 MB. The same song at 320 kbps is about 7 MB. At 64 kbps, it drops to 1.4 MB. The relationship is linear: double the bitrate, double the file size.

Which Bitrate Should You Use?

• Podcasts and voice memos: 64-128 kbps is plenty. Speech does not need high bitrate.
• Music for casual listening: 128-192 kbps gives a good balance of quality and size.
• Archival or professional use: 320 kbps MP3, or better yet, keep WAV/FLAC originals.

Variable vs Constant Bitrate

Constant bitrate (CBR) uses the same rate throughout the file. Variable bitrate (VBR) adjusts based on audio complexity, giving better quality at similar file sizes. Most modern encoders default to VBR, and it is the better choice for most use cases.

For a practical look at how format choice affects file size, see our MP3 vs WAV comparison. If you need to reduce audio files right now, check our guide on 5 methods to reduce audio file size.

Compress Your Audio Files

Need to reduce your audio file size? Use our Audio Compressor to pick a bitrate and compress any audio file in your browser. If you need to convert formats, try WAV to MP3 for significant file size reduction.