Free toolRecording
Audio File Size Calculator
Plan a recording before you start. Estimate compressed audio from bitrate or uncompressed PCM from sample rate, channels and bit depth. Compare decimal and binary units, then work backward from your own file-size limit.
Updated
- Input
- Duration plus bitrate or PCM settings
- Output
- MB, MiB, bytes, max duration
- Privacy
- No audio file, no upload
- Price
- Free, no account
Audio file size calculator
No file upload
Two simple audio-size models
The formulas for compressed bitrate and uncompressed PCM audio.
Compressed bytes = seconds × kbps × 1,000 ÷ 8. PCM bytes = seconds × samples per second × channels × bits per sample ÷ 8. The reverse estimate divides your file limit by bytes per second and rounds down to a whole second.
For example, 60 minutes at 128 kbps contains 57,600,000 bytes of compressed audio data: 57.6 MB or about 54.93 MiB. One minute of 48 kHz, 16-bit stereo PCM contains 11,520,000 bytes before headers.
Use your actual recording settings
Pick the model that matches your encoder; video is excluded.
A compressed bitrate model is useful when you know the encoder’s target rate. A PCM estimate is useful for uncompressed audio. They do not estimate the video track in a camera recording. Check the final downloaded file size before uploading it to a service with a limit.
Questions about this tool
Short answers about what the tool does, what it leaves out and where your data goes.
Are MB and MiB the same?
No. One MB is 1,000,000 bytes; one MiB is 1,048,576 bytes. This calculator shows both and lets you choose the unit for your target limit.
Will the downloaded recording be exactly this size?
No. Container headers, metadata and variable bitrate can change the final file. The estimate models audio data before that overhead, so leave a margin under your limit.
Does the calculator need an audio file?
No. It uses only the duration and settings you enter. It does not fetch, upload or transcribe a recording.
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