Audio File Size Calculator
Audio file size depends on format, sample rate, bit depth, channels, and duration. An uncompressed WAV file at CD quality (44.1 kHz, 16-bit, stereo) uses about 10.6 MB per minute. An MP3 at 128 kbps uses about 0.96 MB per minute. Use the formulas and reference table below to estimate your file sizes.
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: 10-Minute Recording Sizes
Here are file sizes for a 10-minute recording in common formats. These are approximations since compressed formats vary slightly based on audio content.
- WAV (44.1 kHz, 16-bit, stereo): ~101 MB
- WAV (44.1 kHz, 16-bit, mono): ~50 MB
- WAV (48 kHz, 24-bit, stereo): ~165 MB
- FLAC (44.1 kHz, 16-bit, stereo): ~55-65 MB
- MP3 (320 kbps): ~23 MB
- MP3 (128 kbps): ~9.4 MB
- MP3 (64 kbps mono): ~4.7 MB
- OGG Vorbis (128 kbps): ~9.4 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.