Audio Sample Rate Calculator

Audio sample rate and file size are two fundamental concepts in digital audio: sample rate determines audio quality and frequency response, while bit depth and sample rate together determine file size.

The Nyquist-Shannon Theorem: Maximum Reproducible Frequency = Sample Rate ÷ 2 To accurately reproduce audio up to 20,000 Hz (human hearing limit): Minimum sample rate = 20,000 × 2 = 40,000 Hz → standard became 44,100 Hz (44.1 kHz)

Common audio sample rates and their uses:

File size formula (uncompressed audio): File Size (bytes) = Sample Rate × Bit Depth ÷ 8 × Channels × Duration (seconds)

Where:

• Bit Depth = bits per sample (16-bit CD, 24-bit studio)
• Channels = 1 (mono), 2 (stereo)
• ÷ 8 = converts bits to bytes

Worked example, a 5-minute stereo song: At CD quality (44,100 Hz, 16-bit, stereo): File size = 44,100 × 16 ÷ 8 × 2 × (5 × 60) = 176,400 × 300 = 52,920,000 bytes ≈ 50.5 MB (WAV/AIFF)

Same file as MP3 at 320 kbps: 320,000 × 300 ÷ 8 = 12,000,000 bytes = 11.4 MB (77% smaller) Same file as MP3 at 128 kbps: 4.6 MB (91% smaller)

Sizes here use the binary megabyte, 1,048,576 bytes, which is what Windows and most audio software report. Drive manufacturers use the decimal one, 1,000,000 bytes, which is why a “500 GB” disk formats to 465.

Bit depth contribution to dynamic range: Dynamic Range (dB) ≈ Bit Depth × 6.02 16-bit: ~96 dB | 24-bit: ~144 dB

That 6 dB per bit rule only holds for fixed-point audio. 32-bit float does not follow it, and the “192 dB” figure you see quoted for it is simply the rule applied where it does not belong. In a 32-bit float sample, 24 bits hold the mantissa and 8 hold an exponent that slides to follow the signal, which puts the usable range somewhere past 1,500 dB. The practical consequence is the interesting part: you cannot clip a 32-bit float recording. Push the preamp too hard and the waveform looks squared off, but pull the gain down afterwards and it is all still there. That is why field recorders moved to it.