Video File Size Calculator
Know the file size before you hit export. Enter duration, video bitrate and audio bitrate to estimate the output size in KB, MB or GB - and adjust settings until your file fits the platform limit.
How to estimate video file size
- 01Enter the video duration in seconds, minutes or hours.
- 02Enter the video bitrate and audio bitrate in kbps.
- 03Read the estimated size instantly in KB, MB or GB.
Calculator features
Results update on every keystroke - tune bitrates and durations until the size fits your limit.
Sizes are formatted in the most sensible unit automatically, from KB to GB.
A 7% container allowance is added so the estimate matches real MP4 files closely.
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Frequently asked questions
How accurate is the estimate?+
Within a few percent for average-bitrate encodes. Variable bitrate can swing either way with scene complexity.
How do I fit a video under 25 MB?+
Enter your duration, then lower the video bitrate until the estimate reads under 25 MB - or use the Bitrate Calculator in reverse.
Does this work for audio-only files?+
Set video bitrate to 0 and enter your audio bitrate to estimate audio file sizes.
How do I calculate video file size from bitrate?+
Enter the duration, video bitrate, and audio bitrate. The calculator converts the combined bitrate into an estimated file size in KB, MB, or GB.
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