🎚️ Audio
Bit Depth & Sample Rate Calculator
Work out the bitrate and file size of uncompressed audio from bit depth, sample rate, channels and duration. Press Calculate.
About the Bit Depth & Sample Rate Calculator
Pulse-code modulation stores one sample per channel at a fixed rate, with a fixed number of bits per sample. The raw bitrate is therefore bit depth × sample rate × channels. CD audio — 16-bit, 44.1 kHz, stereo — is 1,411.2 kbps, or about 10.6 MB per minute.
Compressed formats throw away or predict information, so their bitrate is a setting rather than a consequence of the format. A 320 kbps MP3 is 320 kbps regardless of sample rate. This calculator reports the uncompressed PCM rate, which is the right figure for WAV/AIFF masters and for estimating storage before encoding.
How the calculation works
- Bitrate (bps) = bit depth × sample rate × channels.
- kbps = bps ÷ 1,000; MB/min = bps × 60 ÷ 8 ÷ 1,000,000.
- File size = bitrate × duration ÷ 8.
- CD audio = 16 × 44,100 × 2 = 1,411,200 bps.
Reference values
| Format | Bit depth | Sample rate | Bitrate |
|---|---|---|---|
| CD audio | 16-bit | 44.1 kHz | 1,411 kbps |
| Studio | 24-bit | 48 kHz | 2,304 kbps |
| High-res | 24-bit | 96 kHz | 4,608 kbps |
| High-res stereo | 24-bit | 192 kHz | 9,216 kbps |
| Multitrack 8ch | 24-bit | 48 kHz | 9,216 kbps |
Worked example: a 24-bit 96 kHz master
A 24-bit, 96 kHz, stereo master is 24 × 96,000 × 2 = 4,608,000 bps, or 4.608 Mbps. One hour is 4.608 × 10⁶ × 3,600 ÷ 8 = 2.074 GB. CD audio at 1,411.2 kbps is 635 MB per hour. A 128 GB card holds about 61 hours of the 96 kHz master.
Higher bit depth lowers the noise floor and gives more headroom for editing, but 16-bit is already sufficient for playback. The practical benefit of 24-bit is in recording and mixing, not in the final delivery format. Compressed formats set their own bitrate, so this calculation applies to uncompressed PCM.
Dithering, noise shaping and delivery
Reducing bit depth is not free. Going from 24-bit to 16-bit discards the quietest detail, and without dithering the truncation produces correlated distortion that is audible on quiet passages. Dither adds a small amount of low-level noise to randomise the error, and noise shaping moves that noise into frequencies where the ear is less sensitive.
The cost is a slightly higher noise floor in the audible band, which is why dithering is applied once, at the final reduction, rather than repeatedly through a chain. For delivery, 16-bit at 44.1 kHz remains the safe universal format; higher rates are useful for recording and processing headroom, not for the file most listeners will play.