The Audio File Size Calculator estimates how large an audio file will be before you record, export or download it. It handles both compressed formats (MP3, AAC) based on bitrate and uncompressed PCM formats (WAV, AIFF) based on sample rate, bit depth and channel count — useful for podcasters, musicians and developers managing storage and bandwidth.
How it works
The tool uses two formulas depending on the format type. Both divide by 8 to convert bits to bytes:
- Compressed (MP3/AAC, constant bitrate): size = bitrate (kbps) × 1000 × duration (s) ÷ 8.
- Uncompressed PCM (WAV/AIFF): size = sample rate (Hz) × bit depth × channels × duration (s) ÷ 8.
Pick a mode, enter the duration in minutes and seconds, then either the bitrate or the sample rate, bit depth and channel count. The estimate updates instantly.
Example
A 320 kbps MP3 running 3 minutes 30 seconds (210 s):
size = 320 × 1000 × 210 ÷ 8 = 8,400,000 bytes ≈ 8.4 MB.
| Format | Settings | Per minute |
|---|---|---|
| MP3 (compressed) | 320 kbps | ~2.4 MB |
| AAC (compressed) | 128 kbps | ~0.96 MB |
| WAV (CD quality) | 44.1 kHz, 16-bit, stereo | ~10.1 MB |
All calculations happen locally in your browser with no uploads.