Video Bitrate Calculator
Given a target file size and a duration, work out the video and audio bitrates that will fit, with the audio track accounted for properly.
The limit you have to come in under.
Subtracted first, because sound is not free.
Video bitrate to aim for
1.04 Mbps
Leaves 128 kbps for audio inside a 25.0 MB target. Aim slightly under: encoders overshoot a little, and containers add a small amount of their own.
Total budget
1.17 Mbps
Duration
3:00
Target
25.0 MB
Only use A2Z Video Tools with content you own, content in the public domain, or content you have permission to download, save, convert or use. Users are responsible for complying with applicable laws and the terms of the source platform.
Working backwards from a limit
Plenty of places will not take a file over a certain size. Rather than exporting, checking, and exporting again at a guess, you can work out in advance what bitrate fits and set the encoder to it once.
The audio is subtracted first, and that order matters. Sound is usually a small share of the total but it is not free, and on a long file at a low target it can eat a surprising proportion. A one hour recording at 128 kbps audio spends about 55MB on sound alone before a single frame of video is stored.
Choosing an audio bitrate
For speech, 64 to 96 kbps is usually transparent enough that nobody notices. For music, 128 kbps is the usual floor and 192 kbps is comfortable. If the video has no meaningful sound at all, setting audio to zero and muting the track frees the whole budget for the picture.
Aim slightly under
Encoders do not hit a target average exactly. They tend to overshoot a little, especially on footage with a lot of motion, and the container adds its own small overhead on top. Leaving two or three per cent of headroom is the difference between a file that fits first time and one that misses by a hair.
When a lower bitrate is the wrong answer
If the bitrate this calculator gives you is very low for the resolution, dropping the resolution is usually a better trade than accepting the low bitrate. A clean 720p picture looks better than a 1080p one starved of bits, because the encoder is no longer being asked to describe more pixels than it can afford. The compression estimator shows where that line falls for a given target.