Podcast File Size Calculator — Duration, Bitrate & Episode Storage
Episode and publishing plan
Enter the total stream bitrate shown by the encoder—not a per-channel rate. For VBR, use the expected average.
Storage assumptions
Optional allowance above the bitrate-only payload.
The number of bytes does not change.
Uses decimal gigabytes to match most hosting and storage plans.
Inputs and calculations stay in this browser. No podcast details are uploaded or included in analytics events.
Podcast storage estimate
Storage budget
Enter valid values to estimate capacity.
Results use the total average encoded bitrate and selected planning overhead.
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How to use the podcast file size calculator
- Enter the finished episode duration. Exclude raw takes unless you intend to publish them.
- Set the average encoded bitrate. Use the total bitrate from the final MP3, AAC, or other delivery file. For variable bitrate, use an expected average.
- Add your catalogue and release schedule. The calculator scales the representative episode to a library, month, and year.
- Adjust the overhead. A small allowance can cover embedded artwork, ID3 tags, chapter data, container overhead, and normal encoder variation.
- Compare with a storage budget. This shows how many same-size episodes fit and the approximate unused capacity.
Podcast file size formula and assumptions
Base bytes = duration seconds × bitrate kbps × 1,000 ÷ 8
Planned episode bytes = base bytes × (1 + overhead % ÷ 100)
Library bytes = planned episode bytes × episode count
The formula treats the entered bitrate as the average rate of the complete encoded stream. It does not multiply by the number of channels. At a fixed total bitrate, mono and stereo have roughly the same file size, although stereo has fewer bits available per channel.
CBR output should be close to the bitrate-only estimate. VBR output depends on the programme material and encoder decisions, so its final average may differ from the target. Artwork, tags, chapters, and container structures are not part of the audio bitrate; the overhead field adds a transparent planning allowance rather than pretending to know their exact size.
Podcast file size examples
| Finished duration | Total bitrate | Base file size | Typical use case |
|---|---|---|---|
| 30 minutes | 64 kbps | 14.4 MB | Efficient speech-led mono delivery |
| 45 minutes | 96 kbps | 32.4 MB | Speech with extra encoding headroom |
| 60 minutes | 128 kbps | 57.6 MB | Common general-purpose planning point |
| 90 minutes | 192 kbps | 129.6 MB | Higher-bitrate or music-heavy programme |
Examples use decimal MB and exclude artwork, metadata, container overhead, and bitrate variation. They are size examples, not codec or publishing recommendations.
Podcast file size FAQ
How do I calculate a podcast file size?
Multiply duration in seconds by bitrate in kbps and by 1,000, then divide by 8. This gives the encoded payload in bytes before separate artwork, metadata, or planning overhead.
How large is a 60-minute podcast at 128 kbps?
About 57.6 MB in decimal units before overhead. With the calculator's default 2% planning allowance, the estimate is about 58.8 MB.
What bitrate should I use for a podcast?
Match the codec, channel layout, audio content, listener experience, and publisher requirements. Speech-only mono can often use less data than stereo or music-heavy content, but always test the final encoded file on representative devices.
Does stereo double the file size?
No, not when you enter the total stream bitrate. A 128 kbps stereo stream is still 128 kbps overall. Stereo changes how the encoder allocates those bits between channels.
Why is my exported file a different size?
VBR encoding, codec and container overhead, embedded artwork, chapters, tags, encoder padding, and rounding can all affect the final result. The calculator is a planning estimate rather than a byte-exact export predictor.
What is the difference between MB and MiB?
MB uses 1,000,000 bytes; MiB uses 1,048,576 bytes. Hosting plans often use decimal units, while some operating systems display binary units.
Are my podcast details uploaded or tracked?
No. Inputs, calculations, copying, and report creation run locally in the browser. Your values are not sent to a calculation backend.