Audio Bitrate Calculator – Uncompressed & Compressed Formats

Audio bitrate is the amount of data processed per second of audio, measured in kilobits per second (kbps). Higher bitrates generally mean better audio quality but larger file sizes. For uncompressed audio (WAV/AIFF), bitrate is determined by sample rate × bit depth × channels. For compressed formats (MP3/AAC), bitrate is a user-selected target that balances quality and file size.

The formula is simple: Sample Rate (Hz) × Bit Depth × Number of Channels = Bitrate (bps). For example, CD-quality audio (44,100 Hz × 16-bit × 2 channels) = 1,411,200 bps = 1,411 kbps. This is the raw data rate before any compression. WAV and AIFF files store audio at this full bitrate.

WAV is uncompressed — every sample is stored as-is, resulting in the largest files. FLAC is losslessly compressed — it reduces file size by ~35-50% while preserving every bit of the original audio (like a ZIP file for audio). MP3 is lossy compressed — it discards audio data deemed less audible to achieve much smaller files, typically 10-25% of the original size depending on the bitrate chosen.

CD-quality audio (44.1 kHz / 16-bit / Stereo) generates approximately 635 MB per hour as uncompressed WAV. The same audio compressed to FLAC takes ~380 MB. As a 320 kbps MP3, it takes only ~144 MB. As a 128 kbps MP3, it takes just ~58 MB — less than 10% of the original WAV size.

For MP3: 128 kbps is acceptable for casual listening, 192 kbps offers good quality, 256 kbps is very good, and 320 kbps is the maximum (transparent for most listeners). For AAC: 128 kbps is roughly equivalent to 160-192 kbps MP3 due to more efficient encoding. For Opus: 64-96 kbps already delivers excellent quality, making it ideal for streaming. The best choice depends on your storage constraints and listening equipment.

Yes, FLAC is mathematically lossless. When you decode a FLAC file back to WAV, the resulting audio data is bit-for-bit identical to the original uncompressed source. FLAC works similarly to a ZIP file — it finds patterns and redundancy in the audio data to reduce size without discarding any information. ALAC (Apple Lossless) works the same way and is also truly lossless.

File size scales linearly with channel count. 5.1 surround (6 channels) produces files exactly 3× larger than stereo (2 channels) at the same sample rate and bit depth. 7.1 surround (8 channels) is 4× larger. Dolby Atmos 7.1.4 (12 channels) is 6× larger. This is why surround sound for film and gaming benefits greatly from compression.

For distribution and listening: 44.1 kHz / 16-bit (CD quality) is sufficient for human hearing. For recording and production: 48-96 kHz / 24-bit provides extra headroom for editing and processing. For archival mastering: 96-192 kHz / 24-bit or 32-bit float ensures maximum flexibility. Higher sample rates capture frequencies beyond human hearing (above 20 kHz) which can be useful in professional workflows but offer no audible benefit for casual listening.