AscendLab

Video tools

Audio File Size Calculator

Free browser tool

Audio File Size Calculator

Estimate audio file size from duration and bitrate for podcasts, voice notes, extracted audio, and media publishing.

Audio file size calculator
Estimate audio file size from duration and bitrate before exporting or uploading.
Audio size result
The estimate uses bitrate math and does not inspect an actual file.

Estimated file size

28.13 MB

Per minute

960 KB

Per hour

56.25 MB

Quick answer

Use this calculator to estimate how large an audio export will be before encoding or uploading.

It is useful for podcast drafts, voice notes, audio extracted from video, and bandwidth planning.

Best inputs

Final duration

Use the edited duration after trimming silence.

Target bitrate

Use the bitrate you plan to export, such as 96, 128, or 192 kbps.

Upload limit

Compare the estimate against platform, email, or LMS size limits.

Audio size method
The calculator uses bitrate math for a quick planning estimate.
File size = duration x bitrate / 8.
Per-minute and per-hour estimates reuse the selected bitrate.
Container overhead and encoder mode can shift actual output.
Example, Assumption, and Limitation
Use the result as a practical estimate or transformation, then confirm edge cases for critical work.

Example

A 30-minute audio file at 128 kbps is roughly 28 MB.

Assumption

The selected bitrate is the average encoded bitrate.

Limitation

Variable bitrate exports, metadata, cover art, and container overhead can change final size.

Common use cases
These pages are built for lightweight browser-side work, examples, and planning.

Podcasts

Estimate episode size before upload.

Voice notes

Plan delivery size for spoken audio.

Video audio

Estimate extracted audio size.

Bandwidth

Estimate transfer size for training or course media.

Frequently asked questions

How is audio file size estimated?

The tool multiplies duration by bitrate and converts bits to bytes. It is a practical estimate, not a file inspection.

Does the format matter?

Format and encoder behavior can affect the final file, but bitrate and duration are the main planning inputs.

Can I use this for MP3, M4A, AAC, or Opus?

Yes, if you know the target bitrate. The estimate is useful across common audio formats.

Does this upload audio?

No. It only calculates from typed values in your browser.

Suggested workflow

Audio planning workflow

Estimate audio size, extract audio if needed, then prepare video or audio assets.