Video Bitrate Calculator
Calculates the bitrate you need for a target size and duration.
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THE BITRATE THAT FITS THE TARGET SIZE.
The Video Bitrate Calculator does the arithmetic between the file size and the bitrate of a video. For files it works in two directions: if you enter the target size (in MB or GB) and the duration, it finds the bitrate needed; if you enter the bitrate and the duration, it tells you how much the file will come to. The third mode is for live streaming: pick YouTube or Twitch with a resolution and frame rate, and it shows the recommended video bitrate, audio bitrate and keyframe interval from the platform's official help page; enter a duration and it also works out how much data the stream will send. A link to the page the values come from is below the result. It is used to find the setting that will fit a platform's or a messaging app's size limit, to estimate the disk a recording needs, or to make sense of an encoding setting.
The target size is the total of picture and sound; that is why the audio bitrate (no audio, 96, 128, 192 or 320 kb/s) is chosen separately and deducted from the total, with the rest given to the picture. The result shows the total, video and audio bitrate, the file size and the FFmpeg equivalent (the -b:v and -b:a values). The calculation takes 1 MB = 1024 × 1024 bytes and 1 kb/s = 1000 bits. If the video bitrate falls below 500 kb/s, you are warned that blocking will show at 720p and above. A bitrate is an average value; with variable-rate encoding the real size drifts a little.
From start to finish
- Choose the direction. Bitrate from a target size, file size from a bitrate, or the recommended bitrate for live streaming.
- Enter the duration and the target. Write the duration in minutes and seconds and the target size in MB or GB; choose the audio bitrate.
- Use the result. Put the video bitrate into your encoder or into the “Video Compressor” tool.
Frequently asked questions
Which bitrate to fit a 10-minute video into 100 MB?
The total comes to about 1398 kb/s. With 128 kb/s set aside for audio, about 1270 kb/s is left for the picture; that is reasonable for 720p and marginal for 1080p.
Why does the result come out a little different from the target?
Encoders hit the bitrate as an average, and the container file (MP4, MKV) adds a few header bytes. Choosing a value about 1–2% under the target is safe.
What if I want to do the arithmetic myself?
Bitrate (kb/s) = size (MB) × 1024 × 1024 × 8 ÷ duration (s) ÷ 1000. Subtract the audio bitrate from that and the video bitrate is left.
Is the data I enter sent to the server?
No. This tool runs entirely in your browser; nothing you type or add is sent to the RUPO Studio server. It keeps working while the page is open even if your internet connection drops. No account needed. It is free to use: there is no hourly or daily limit, and we don't make you watch an ad before you see the result.
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