Bitrate describes how much data a video stream uses over time. It is commonly shown in megabits per second, or Mbps.
Why bitrate matters
Two cameras can both record 4K video but use very different bitrates. One might record 4K at 60 Mbps while another records a high-quality intraframe format at 600 Mbps. The second file uses roughly ten times as much data per second.
Bitrate and file size
A useful conversion is:
megabytes per second = megabits per second รท 8
So a 120 Mbps recording stream is roughly 15 MB per second before file-system overhead.
Does a higher bitrate always mean better video?
No. Codec efficiency, bit depth, chroma subsampling, image complexity, sensor quality, processing, and compression method all matter. A newer codec can sometimes preserve similar quality at a lower bitrate than an older one.
Why this matters when choosing a memory card
The card must sustain the data rate the camera writes. That is why some recording modes work with V30 cards while others require V60 or V90.
Read the memory-card speed guide.
Real product examples
- Canon EOS R50 at about 120 Mbps in standard 4K
- Sony ZV-E10 II recording modes up to 600 Mbps
- DJI Osmo Pocket 3 with a maximum listed video bitrate of 130 Mbps
Turn bitrate into recording time
Once you know bitrate, you can estimate how much footage fits on a card.
Use bitrate to estimate recording time on 128GB, 256GB, or 512GB cards.
Keep frame rate in context
High frame rates often require higher bitrates or different recording modes, but frame rate and bitrate are not the same thing.