Audio file size calculator: WAV, AIFF and MP3

The formula

Uncompressed audio (WAV, AIFF, Broadcast WAV) stores every sample, so its size is sample rate × (bit depth ÷ 8) × channels × seconds bytes, plus a small header and any embedded metadata. Compressed formats at a constant bitrate are simpler: kilobits per second × 1,000 ÷ 8 × seconds.

Worked example: one minute of CD-quality stereo is 44,100 × 2 × 2 × 60 = 10,584,000 bytes, about 10.58 MB. Its data rate, 44,100 × 16 × 2 = 1,411,200 bits a second, is where the familiar “1,411 kbps” figure comes from.

MB here is a million bytes, as macOS reports it. Windows divides by 1,048,576 and still writes “MB”, so the same file looks about 5% smaller there; the calculator shows both.

One minute of stereo at common settings

Planning a session

Multiply by the track count: a 4-minute song with 24 mono tracks at 48 kHz / 24-bit is 24 × 48,000 × 3 × 240 bytes, about 829 MB before any bounces or comps. Lossless compression (FLAC, ALAC) usually saves a good share of that, but how much depends on the audio, so no formula can predict it exactly.