How is compressed audio size calculated?

Size equals bitrate in kbps times 1000 times duration in seconds, divided by 8. A 320 kbps track running 3 minutes 30 seconds is about 8.4 MB.

How is uncompressed WAV size calculated?

For PCM the size is sample rate (Hz) times bit depth times channels times duration in seconds, divided by 8. CD-quality 44100 Hz, 16-bit, stereo audio is about 10.1 MB per minute.

Does anything leave my device?

No. All calculations happen locally in your browser with no uploads.

Audio File Size Calculator

Estimate audio file size for MP3, AAC or uncompressed WAV.

Audio file size calculator

Work out how big an audio file will be — either for compressed formats like MP3 and AAC (from the bitrate) or for uncompressed PCM like WAV and AIFF (from sample rate, bit depth and channel count).

Compressed audio uses bitrate × 1000 × seconds ÷ 8. Uncompressed PCM uses sample rate × bit depth × channels × seconds ÷ 8. Pick a mode, enter your numbers, and the estimate updates instantly — all in your browser.