What Is Audio Bit Depth? 16-Bit vs. 24-Bit Explained

Audio bit depth describes the number of bits used to represent each sample value in integer PCM audio. More bits allow more possible sample values, which reduces the size of each quantization step for a given fixed range. This affects the theoretical difference between the largest signal and quantization noise; it is not a direct measure of how good a particular recording sounds.

For example, 16-bit integer PCM has 2¹⁶, or 65,536, possible values per sample; 24-bit integer PCM has 2²⁴, or 16,777,216. Those counts describe the representation, not the quality of the microphone, room or performance. Audacity's bit-depth guide explains the sample-format and file-size relationship.

16-bit vs. 24-bit audio

Question	16-bit integer PCM	24-bit integer PCM
Possible values per sample	65,536	16,777,216
Theoretical dynamic-range approximation	About 96 dB using the common 6 dB per bit rule of thumb.	About 144 dB using the same approximation.
Common role	A delivery format when required, including standard audio CD.	A recording or working format when the equipment and workflow support it.
PCM storage at the same rate, duration and channels	Smaller when packed as 16 bits per sample.	About 1.5 times the sample payload when packed as 24 bits per sample.

The dynamic-range figures are theoretical approximations, not a promise that an interface, microphone or recording captures that range. Converter performance, analog noise, gain and the room can set practical limits. Higher bit depth does not make a clipped take clean or turn a noisy recording into a quiet one.

Which bit depth should you use?

For recording and editing, 24-bit PCM is a common choice when your hardware and project support it, because its larger theoretical range gives more room above the quantization floor when setting conservative recording levels. It does not prevent clipping at the microphone, preamp, converter or later processing stage. Make a short test at your loudest expected level and listen back.

For delivery, follow the recipient's actual specification. A well-prepared 16-bit file can be suitable for a destination that requires it; a 24-bit export is not automatically an audible improvement. Keep the higher-resolution source or project when available, and compare the exported file at a similar listening level.

Bit depth vs. sample rate vs. bitrate

Term	What it describes	Example
Bit depth	The representation of each integer PCM sample value.	16-bit or 24-bit PCM.
Sample rate	How many sample frames are represented each second.	44,100 or 48,000 frames per second.
Bitrate	Data per unit of time in a stream or file, often expressed in kbps.	A 192 kbps MP3 or the calculated payload rate of uncompressed PCM.

These settings are related to data size but answer different questions. See audio sample rate explained and audio bitrate explained. A compressed MP3's bitrate should not be treated as a PCM bit-depth field.

How much larger is a 24-bit WAV?

For uncompressed, packed PCM, estimate the audio payload with sample rate × bits per sample × channels × seconds ÷ 8. At 48 kHz, one minute of stereo 16-bit PCM contains 48,000 × 16 × 2 × 60 ÷ 8 = 11,520,000 bytes, or 11.52 MB. At 24 bits under the same assumptions, the payload is 17,280,000 bytes, or 17.28 MB.

These are decimal MB and exclude headers and metadata. WAV is a container and may use other encodings or store valid bits in a wider container, so inspect the actual file rather than assuming its size from the extension. The audio file size calculator estimates other PCM settings.

How to check a WAV file's bit depth

1. Open the WAV file inspector and select a compatible local RIFF/WAVE file.
2. Read the stored encoding, sample rate, channels and bit-depth fields. For extensible WAV, note the distinction between container bits and valid bits when provided.
3. Compare the report with the delivery requirement, and keep the original. The inspector reads file structure; it does not determine the quality or history of the sound.

The inspector supports integer PCM and floating-point RIFF/WAVE variants. It does not inspect MP3 or FLAC, repair audio, or prove that a 24-bit file came from a 24-bit recording. The WAV inspection guide explains the fields and limitations.

What happens when you change bit depth?

Exporting a higher-resolution working file to lower integer bit depth requires quantization. Dither adds a carefully chosen low-level noise signal to reduce correlated quantization distortion; it is commonly considered at the final reduction to the requested integer format. The dither guide explains the tradeoff and why a noise-shaping choice is separate.

Exporting a 16-bit source as 24-bit does not recreate details absent from the source. Processing, resampling or changing bit depth can change samples even when the resulting container is WAV. Keep the original and use the destination's required settings.

What about 32-bit float?

Floating-point audio uses a different representation from fixed integer PCM, so its number of bits should not be compared as if it simply offered more evenly spaced integer levels. Floating-point processing can represent values above the usual 0 dBFS reference inside a compatible workflow, which can be useful while mixing. That does not undo clipping already captured at an earlier stage, and a later integer export still has a finite range.

Common questions

Is 24-bit always better than 16-bit?

No. It provides a larger theoretical integer range, but source quality, noise, processing and playback matter. Use a format appropriate to the recording and delivery requirements.

Does higher bit depth increase volume?

No. Bit depth changes sample representation, not an automatic gain control. Loudness and clipping must be evaluated separately.

Can I hear the bit depth just by looking at a file name?

No. A filename or WAV extension does not establish its sample format or source history. Inspect the file and listen to the actual recording.