Video bitrate

Enter the file size budget, total duration and average audio bitrate. The result is the average bitrate available to the video stream. Size and duration each have one explicit unit. MB/GB are decimal; MiB/GiB use powers of 1024. A kb/s is 1000 bits per second, not kilobytes.

Reserve sets aside a percentage of the file budget for the container, metadata and other streams. The initial 2% is adjustable and is only a planning assumption. With no reserve, 100 MB for 100 seconds provides 8000 kb/s in total; after 128 kb/s audio, video gets 7872 kb/s.

Formula: video bitrate = 8 × size ÷ duration × (1 − reserve/100) − audio bitrate, after converting units. A zero audio bitrate means no audio. Audio must leave a positive budget for video.

This calculator neither encodes nor analyzes a video and cannot promise an exact final file size. Variable bitrate, encoder behavior, audio peaks and container overhead affect the result. Use an average target bitrate with an encoding workflow that can meet the budget, then check the output file. The displayed target is rounded down to three decimal places. Settings are remembered while navigating; calculations stay in this browser.