Audio File Size Calculator
Calculate audio file size from track duration, sample rate (44.1-192 kHz), bit depth, and channels.
Compares WAV, lossless FLAC, and lossy MP3 and AAC sizes.
Audio file size is determined by three factors: bit rate, sample rate, channel count, and duration. Understanding this calculation is essential for storage planning, streaming budget estimation, and format selection in music production and distribution.
Uncompressed audio (WAV/AIFF) formula: File Size (bytes) = Sample Rate × Bit Depth × Channels × Duration (seconds) ÷ 8
Divide by 8 to convert bits to bytes.
Where:
- Sample Rate = samples per second (Hz). Common: 44,100 Hz (CD quality), 48,000 Hz (video), 96,000 Hz (studio)
- Bit Depth = bits per sample. Common: 16-bit (CD), 24-bit (professional), 32-bit float (editing)
- Channels = 1 (mono), 2 (stereo), 6 (5.1 surround)
- Duration = length in seconds
Compressed audio (MP3/AAC) formula: File Size (bytes) = Bit Rate (bps) × Duration (seconds) ÷ 8
Common MP3 bit rates and quality:
| Bit Rate | Quality | Size per Minute |
|---|---|---|
| 128 kbps | Acceptable (streaming) | ~960 KB |
| 192 kbps | Good (most listeners) | ~1.44 MB |
| 256 kbps | Very good (audiophile) | ~1.92 MB |
| 320 kbps | Excellent (near-lossless) | ~2.40 MB |
Uncompressed reference:
- CD quality (44.1 kHz, 16-bit, stereo): 10.1 MB per minute
- Studio quality (96 kHz, 24-bit, stereo): 34.6 MB per minute
Worked example: A 4-minute song at CD quality WAV: Size = 44,100 × 16 × 2 × 240 / 8 = 338,688,000 bytes = ~338 MB
Same song as 320 kbps MP3: Size = 320,000 × 240 / 8 = 9,600,000 bytes = ~9.6 MB
Compression ratio: 338 / 9.6 = 35:1 — MP3 achieves 35× size reduction with minimal perceptible quality loss at 320 kbps.
Streaming data usage: 1 hour of Spotify (320 kbps) = ~144 MB/hour. Lossless (Apple Lossless ALAC at 1,411 kbps) = ~635 MB/hour.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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