The audio file size calculator estimates how large an audio file will be based on duration, format, and bitrate/quality settings. Useful for planning storage, upload quotas, or comparing format tradeoffs.
File Size Calculator
Choosing the Right Audio Format
Audio format choice involves tradeoffs between file size, quality, and compatibility. For most purposes, the choice comes down to lossless vs lossy and which container format your workflow supports.
Lossless Formats (WAV, AIFF, FLAC)
WAV and AIFF are uncompressed — they store every sample directly. A 3-minute stereo WAV at 44.1 kHz / 16-bit takes about 31.5 MB. FLAC is lossless compression — identical audio quality but 40-60% smaller. Use FLAC for archiving and distribution where quality must be preserved. WAV/AIFF for professional DAW sessions where file size is less important than simplicity and compatibility.
Lossy Formats (MP3, AAC, OGG)
Lossy formats discard audio information the human ear is least likely to notice. At high bitrates (256-320 kbps), the difference from lossless is inaudible on most equipment. MP3 is universally supported. AAC gives better quality than MP3 at the same bitrate (used by Apple, YouTube, Spotify). OGG is open-source and efficient. Use lossy formats for streaming, distribution, and storage where bandwidth matters.
Frequently Asked Questions
Is this audio file size calculator free?
Yes, completely free with no signup required.
How large is a 3-minute MP3 at 320kbps?
A 3-minute (180 second) MP3 at 320 kbps = 320,000 bits/sec × 180 sec = 57,600,000 bits = 7.2 MB. The calculation is: (bitrate in kbps × duration in seconds) / 8 / 1024 = MB.
How does FLAC compare to WAV in file size?
FLAC (Free Lossless Audio Codec) is lossless compression — audio quality is identical to WAV but file size is typically 40-60% of WAV. A 5-minute WAV file at 44.1kHz/16-bit stereo is about 52 MB; the same content as FLAC is typically 25-30 MB. Unlike MP3, FLAC doesn't sacrifice quality.
What bitrate should I use for MP3?
128 kbps: acceptable for casual listening, noticeable artifacts on complex music. 192 kbps: good quality, difficult to distinguish from CD on most speakers. 320 kbps: transparent quality, essentially indistinguishable from WAV on standard equipment. For archiving, use FLAC. For distribution, 192-320 kbps MP3 or AAC.
What is sample rate and how does it affect file size?
Sample rate is how many times per second the audio is sampled. CD quality is 44,100 Hz (44.1 kHz). Professional audio uses 48 kHz or 96 kHz. Higher sample rates produce larger files. A 44.1 kHz WAV is about 9% smaller than the same recording at 48 kHz, and 46% smaller than 96 kHz.