Audio File Size Reference Guide
Audio file size depends on format, sample rate, bit depth, channels, and duration. An uncompressed WAV at CD quality (44.1 kHz, 16-bit, stereo) uses about 10.6 MB per minute. MP3 at 128 kbps uses about 0.96 MB per minute. The table below gives reference sizes for common formats and durations.
Start RecordingHow Audio File Size Is Calculated
For uncompressed audio (WAV, AIFF), the formula is straightforward: Sample Rate x Bit Depth x Channels x Duration in seconds, divided by 8 to convert bits to bytes. For example, 44,100 samples/sec x 16 bits x 2 channels x 60 seconds = 84,672,000 bits = 10,584,000 bytes = about 10.1 MB per minute. For compressed formats like MP3, the formula is simpler: Bitrate x Duration. A 128 kbps MP3 uses 128,000 bits per second, which is 960,000 bytes (about 0.94 MB) per minute. FLAC is lossless compressed and typically achieves 50-60% of the original WAV size.
Quick Reference: File Sizes by Format and Duration
These are approximations. Compressed formats vary slightly based on audio content. Use the LUFS normalizer to adjust loudness after exporting, or the audio trimmer to cut files down before sharing.
| Format | 1 min | 10 min | 60 min |
|---|---|---|---|
| WAV 44.1 kHz 16-bit stereo | ~10.1 MB | ~101 MB | ~605 MB |
| WAV 44.1 kHz 16-bit mono | ~5 MB | ~50 MB | ~302 MB |
| WAV 48 kHz 24-bit stereo | ~16.5 MB | ~165 MB | ~990 MB |
| FLAC 44.1 kHz 16-bit stereo | ~5.5-6.5 MB | ~55-65 MB | ~330-390 MB |
| MP3 320 kbps | ~2.3 MB | ~23 MB | ~138 MB |
| MP3 128 kbps | ~0.94 MB | ~9.4 MB | ~56 MB |
| MP3 64 kbps mono | ~0.47 MB | ~4.7 MB | ~28 MB |
| OGG Vorbis 128 kbps | ~0.94 MB | ~9.4 MB | ~56 MB |
Which Format to Use
Use WAV when recording and editing, because it preserves full quality and you can always compress later. Use FLAC for archiving, since it is lossless but about half the size of WAV. Use MP3 at 128-192 kbps for distribution: podcasts, sharing online, email attachments. Use OGG if you need an open-source compressed format, though MP3 has broader compatibility. Do not record directly to MP3, because you cannot recover the quality that compression removes.
- Recording and editing: WAV (full quality, no compromises)
- Archiving: FLAC (lossless, smaller than WAV)
- Podcasts and sharing: MP3 128 kbps mono
- Music distribution: MP3 192-320 kbps or FLAC
- Open-source projects: OGG Vorbis
Frequently asked questions
How large is a 1-hour podcast recording?
A 1-hour podcast recorded as WAV (44.1 kHz, 16-bit, mono) is about 302 MB. The same content as MP3 at 128 kbps mono is about 56 MB. For final distribution on podcast platforms, the MP3 file is standard.
Why is WAV so much larger than MP3?
WAV is uncompressed, storing every audio sample at full precision. MP3 uses psychoacoustic compression to remove audio data that most people cannot hear, reducing file size by 5-12x depending on bitrate. The tradeoff is a small, usually inaudible, loss in quality.
Does FLAC save much space compared to WAV?
FLAC typically reduces file size to 50-60% of the equivalent WAV. A 100 MB WAV file becomes roughly 55 MB as FLAC with no quality loss. It is worth using for archiving large recordings.
Does higher bitrate always mean better quality?
Yes, up to a point. For MP3, most people cannot hear a difference above 192 kbps for music or 128 kbps for speech. Going from 128 to 320 kbps doubles the file size but the quality improvement is minimal for voice content.
How big is a 1-hour WAV recording?
A 1-hour WAV at 44.1 kHz, 16-bit, stereo is about 605 MB. Mono cuts that in half to about 302 MB. Record with Orec for free in your browser (no signup, no download) and export to WAV or MP3 depending on your storage needs.
How do I calculate audio file size?
For WAV: Sample Rate x Bit Depth x Channels x Seconds, divided by 8 for bytes. For MP3: Bitrate x Seconds divided by 8. Orec lets you record in both formats for free with no signup or download, so you can pick the right size for your needs.
What audio format has the smallest file size?
MP3 at 64 kbps mono produces the smallest files at about 0.47 MB per minute. For better quality, 128 kbps is about 0.94 MB per minute. Orec lets you export to both WAV and MP3 for free, with no signup or download, right in your browser.
How much storage do I need for podcast recording?
Plan for about 50 MB per 10 minutes when recording in WAV mono. A 1-hour episode is roughly 302 MB as WAV. After export to MP3, that drops to about 56 MB. Orec is free with no signup or download and lets you record directly in your browser, then choose your export format.