Video Bitrate Calculator Guide
Reference for estimating target video bitrate from duration and desired file size before compression or publishing.
Quick answer
Use Video Bitrate Calculator when you know a video duration and target file size, but need a realistic bitrate target before compressing. It helps turn "make this under 25 MB" into a setting you can test.
What this tool does
The calculator estimates total bitrate and video bitrate after accounting for duration and optional audio bitrate. It does not re-encode files; it gives a planning number for compression tools.
Step-by-step use
- Check source duration in Video Info Inspector.
- Enter the desired output size.
- Set an audio bitrate if the output keeps sound.
- Use the estimated video bitrate as a starting point.
- Compress a short sample and adjust for readability or motion.
Example
A 60-second onboarding clip needs to fit under 20 MB. If audio uses 96 kbps, the calculator gives a rough video bitrate budget. Use that as a starting point, then review the actual output from Video Compressor.
Review example
Before processing a long clip, test the estimated bitrate on a short section with motion and text. Source complexity, codec, and audio settings can move the final size away from the estimate.
Assumptions and limits
The result is an estimate, not a guaranteed output size. Containers, codec behavior, variable bitrate encoding, and scene complexity can change the final file size.
Common mistakes
Ignoring audio bitrate. Speech or music can take a meaningful part of the size budget.
Expecting the exact final size. Bitrate planning helps choose settings, but the encoder decides the final result.
Forgetting readability. UI recordings may need more bitrate than simple talking-head or static clips.
Next steps
- Video Compressor — test the bitrate target with a real export
- Video Info Inspector — read source duration and dimensions
- Audio File Size Calculator — estimate the audio part separately