Video Bitrate Calculator for File Size
Estimate video bitrate from duration, target file size, and audio bitrate, or estimate output file size from chosen bitrates.
Recommended video bitrate
1,237 kbps
Estimated size
97.27 MB
Use this calculator when you need a target bitrate before compressing or encoding a video.
It is especially useful for upload limits, email attachments, course platforms, and social media file-size constraints.
Real duration
Use the final edited duration, not the original source runtime.
Target file size
Use the platform upload limit or your desired delivery size in MB.
Audio bitrate
Include the planned audio bitrate so the video bitrate budget is realistic.
Example
A 10-minute video targeting 100 MB with 128 kbps audio needs roughly 1,237 kbps video bitrate.
Assumption
The MB estimate is a practical browser-side approximation for planning.
Limitation
Final encoder output may differ when using variable bitrate, scene complexity, or different codecs.
Upload limits
Choose bitrate before compressing for a strict file limit.
Course videos
Plan lecture file sizes before export.
Product demos
Balance quality and size for web publishing.
Video QA
Compare expected size against actual export size.
What does a video bitrate calculator do?
It estimates a video bitrate from duration and target file size, or estimates file size from selected audio and video bitrates.
Is the result exact?
No. It is a planning estimate. Codec efficiency, container overhead, variable bitrate behavior, and encoder settings can change the final file size.
Should audio bitrate be included?
Yes. The total bitrate budget includes both video and audio, so subtracting audio bitrate gives a better video bitrate target.
Does this tool upload video files?
No. It uses typed numbers only and runs in the browser.
Suggested workflow
Video size planning workflow
Estimate the bitrate, inspect the source, then compress or convert the video.