Video Bitrate Calculator
Choose what you want to calculate, then enter the other two values - file size, duration, and bitrate are all related, so any two determine the third.
Last updated: September 22, 2026
Frequently asked questions
What bitrate should I target for a YouTube upload?
It depends on resolution and frame rate - YouTube's own recommendations are roughly 8 Mbps for 1080p at 30fps and around 35-45 Mbps for 4K at 30fps (SDR), higher for 60fps or HDR content. Use this calculator with your target resolution's recommended bitrate to find the resulting file size for your video's duration.
Why is my file size bigger than expected for the bitrate I used?
The bitrate you set is usually video-only - most video files also include an audio track (commonly 128-320 kbps) added on top, plus container overhead, so the final file is somewhat larger than the video-bitrate-only calculation shown here.
What's the difference between Mbps and MB in this calculator?
Mbps (megabits per second) measures bitrate - a rate over time. MB (megabytes) measures total file size - a fixed amount of data. There are 8 bits in a byte, which is why the formulas here multiply or divide by 8 when converting between the two.
Does this account for variable bitrate (VBR) encoding?
No - this calculates an average, constant bitrate across the whole duration. VBR encoding varies the instantaneous bitrate (using more data for complex/high-motion scenes and less for static ones), but the average bitrate still determines the total file size the same way for a given duration.
How do I calculate the combined bitrate for video plus audio?
Calculate your video bitrate and audio bitrate separately (audio is typically a fixed 128-320 kbps, listed in your encoder settings), then add them together before estimating total file size, since this calculator's bitrate field represents one stream at a time.
What bitrate keeps a 10-minute video under a specific file size limit, like 500MB?
Enter your file size limit and duration, and select "Bitrate" as what to find - for 500MB over 10 minutes (600 seconds), that works out to about 6.7 Mbps average bitrate.