Video bitrate calculator

What this tool does

total_kbps = file_bytes * 8 / duration / 1000. An audio allowance is subtracted to estimate video kbps. That is an estimate because container overhead exists.

How to use it

1. Enter size and duration, or drop a file to fill duration and bytes.
2. Set an audio bitrate assumption.
3. Read total and video kbps.

Privacy

This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.

ConvertPass does not include your input in analytics, URLs, or error reports. Encoding: N/A. Limit: 80 MB if using a file (80.00 MB).

Limitations

• Overhead is not modelled.
• Variable bitrate averages over the whole file.

Example

8.1 MB, 12.4 s, audio 128 kbps

total ≈ 5350 kbps, video ≈ 5222 kbps

Troubleshooting

The number looks far from your encoder setting

Encoders speak in target bitrate; files include headers, audio, and VBR swings. Compare against the inspector’s estimate, not the encoder’s wish.

FAQ

Is this the same as ffprobe?

No. ffprobe reads headers. This calculator uses size and duration, optionally filled from a local file.

What audio default should I use?

128 kbps is a common AAC stereo default. Use 192 or 256 if you know the encode is higher.

Can I plan a 4K upload?

You can estimate bytes from a target bitrate. Whether a platform accepts 4K is a separate policy.

Does dropping a file upload it?

No. Only duration and size are read when the browser can decode metadata.