Audio File Size Calculator
Calculate audio file size based on duration and format. Estimate storage requirements for different audio codecs and bitrates.
How to Use This Calculator
- Enter your audio duration in seconds (or convert minutes to seconds: minutes × 60).
- Select your audio format from the dropdown (MP3, AAC, FLAC, WAV, etc.).
- If using "Custom", enter your specific bitrate in kbps.
- The calculator displays the estimated file size in bytes, KB, MB, or GB.
Audio File Size Formula
Audio file size is calculated from bitrate and duration:
Example: MP3 at 128 kbps for 3 minutes (180 seconds): File Size = (128 × 1,000 × 180) ÷ 8 = 2,880,000 bytes = 2.88 MB.
Full Description
Understanding audio file sizes is essential for planning storage, estimating download times, and managing bandwidth. File size depends on two main factors: bitrate (data rate) and duration. Different audio formats use different bitrates to achieve similar quality, with lossless formats requiring much higher bitrates than compressed formats.
Lossy formats (MP3, AAC) use compression algorithms to reduce file size while maintaining acceptable quality. Lossless formats (FLAC, WAV) preserve all audio data, resulting in larger files. The trade-off is file size vs. audio quality—lossy formats are much smaller but lose some audio information, while lossless formats are larger but preserve full quality.
This calculator helps you estimate file sizes for different formats and durations. Use it to plan storage needs, estimate transfer times, and understand the trade-offs between different codecs. Remember that actual file sizes may vary slightly with variable bitrate encoding, but these estimates provide a good starting point for planning.
Frequently Asked Questions
How is audio file size calculated?
File size = (Bitrate × Duration) ÷ 8. Bitrate is measured in kilobits per second (kbps), so multiply by duration in seconds, then divide by 8 to convert to bytes. For example, 128 kbps for 3 minutes = (128 × 1000 × 180) ÷ 8 = 2.88 MB.
What bitrate should I use?
For MP3: 128 kbps is standard for most uses, 192 kbps offers better quality, 320 kbps is near-CD quality. For lossless formats (FLAC, WAV), bitrate is fixed at 1411 kbps (16-bit) or 2117 kbps (24-bit).
What's the difference between MP3, AAC, FLAC, and WAV?
MP3 and AAC are lossy formats (compressed, smaller files). FLAC is lossless compression (same quality as WAV, smaller files). WAV is uncompressed (largest files, best quality). Choose based on your quality needs and storage constraints.
How accurate are these estimates?
These are estimates based on constant bitrate (CBR). Actual file sizes may vary slightly with variable bitrate (VBR) encoding, which adjusts bitrate based on audio complexity. VBR files are often 10-20% smaller than CBR estimates.