Video File Size & Bitrate Calculator
Work out how big a video will be at a given bitrate, or which bitrate gets it under a size limit.
File size is bitrate times duration. This calculator does it both ways: enter the video and audio bitrate to get the size, or enter a target size to get the maximum video bitrate you can export with. Presets cover common limits such as Discord (10 MB), WhatsApp (16 MB) and email attachments (25 MB), with a small safety margin for the container.
How it works
- Pick a mode Bitrate to size, or size to bitrate.
- Enter duration and bitrates Duration as m:ss or seconds, video in Mbit/s, audio in kbit/s.
- Use the result Set it as the target bitrate in your export settings.
FAQ
How do I get a video under 10 MB?
Choose Target size, tap Discord 10 MB and enter the duration. For a 30-second clip with 128 kbit/s audio that is about 2.5 Mbit/s video, which still looks good at 720p.
Why is my file bigger than calculated?
Containers and variable bitrate add 1 to 3 percent, and some encoders overshoot. Leave a margin, the presets already subtract 3 percent.