Bit Depth Explained: 16-bit vs 24-bit vs 32-bit Float
Sample rate tells you how many times per second the sound is measured. Bit depth tells you how finely each measurement is stored. More bits means a finer scale between the quietest and loudest value.
What each bit depth gives you
| Bit depth | Theoretical dynamic range | Typical use |
|---|---|---|
| 8-bit | about 48 dB | Old or very low-quality audio. Audible hiss. |
| 16-bit | about 96 dB | CDs, most speech datasets, general delivery. |
| 24-bit | about 144 dB | Recording and editing. Lots of headroom. |
| 32-bit float | very large (floating point) | Internal processing and some recorders. Can hold levels above 0 dBFS inside the file. |
In practice, no microphone or room is quiet enough to use all 144 dB of a 24-bit file. The benefit of 24-bit is not that it sounds better when played back. It is that you can record at a safer, lower level without losing quality, because the noise from the quantization is far below the noise of the room.
File size
Uncompressed size is easy to calculate: sample rate × bytes per sample × channels × seconds.
- 16 kHz, mono, 16-bit: 32,000 bytes per second, about 1.9 MB per minute.
- 48 kHz, mono, 24-bit: 144,000 bytes per second, about 8.6 MB per minute.
- 44.1 kHz, stereo, 16-bit: 176,400 bytes per second, about 10.6 MB per minute.
Which to choose
- Delivering speech data: follow the project specification. 16-bit is the most common requirement, and it is plenty for speech.
- Recording: use 24-bit if your device offers it, then convert to the required depth at the end.
- 32-bit float: useful if you cannot control levels, because the recording will not clip inside the file. Convert it to 16 or 24-bit for delivery and check the level first.
A note on conversion
Reducing bit depth, for example from 24 to 16, throws away the finest detail. Professional tools add a tiny amount of noise called dither to hide the rounding error. Raising bit depth, from 16 to 24, only changes the container: it does not bring back detail that was never recorded. The WAV files that the Sayvoi converter writes are 16-bit, which suits most speech delivery requirements. If a project requires 24-bit, convert with a desktop tool instead.
Check the bit depth of your files
The quality checker reads the bit depth of WAV and FLAC files from their headers, and flags any file that does not match the depth you require.
Convert your audio files for free in your browser, without uploading them to any server.
Open the converter