Video size & bitrate calculator
Fit a size limit
Video bitrate to aim for
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How big is my recording?
Approximate file size
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How the numbers work
File size is just bitrate × length. To fit a limit, take the target size in bits, subtract the audio, and divide by the number of seconds. If the bitrate that leaves is low, dropping resolution keeps the picture sharp instead of blocky — that's why a 5-minute video for email usually needs to go to 720p or below.