Bitrate Calculator
Need a video to land under a size limit? Enter the target size and the length. This tool gives you the bitrate to set so the file fits.
Enter a target size and a length to see the bitrate.
Set your export a little below this figure. Audio and container overhead add to the file, so a small margin keeps you under the size cap.
How It Works
Enter the target file size and its unit, then the length and a time unit. The needed bitrate appears in Mbps and kbps.
This runs the video size math in reverse. Instead of bitrate to size, it goes from size and length back to bitrate.
Set your export a touch below the result to leave room for audio and container overhead.
The Formula
Convert the target size to bytes, then to bits by multiplying by 8.
A 600 MB target is 600,000,000 bytes, or 4,800,000,000 bits.
Divide by the length in seconds. Over 600 seconds, that is 8,000,000 bits per second, or 8 Mbps.
Worked Example
You want a 10 minute video to come in around 600 MB.
600 MB is 4,800,000,000 bits. The length is 600 seconds.
Divide and you get 8,000,000 bits per second, so set the bitrate to about 8 Mbps.
Common Uses
- Fitting a clip under an upload or attachment size cap.
- Picking a bitrate for a streaming platform target.
- Trading quality against size for a fixed storage budget.
- Working out the bitrate a finished file already uses.