Video file size calculator
Estimate video file size by multiplying its duration by the combined video and audio bitrates, then dividing by eight.
This calculator runs entirely in your browser - nothing is uploaded, nothing is stored, and nothing you type leaves the page.
About 614.40 MB
Estimated file size at the average bitrates above.
| Video | 600.00 MB |
|---|---|
| Audio | 14.40 MB |
| Combined bitrate | 8.192 Mbps |
| Size per minute | 61.44 MB |
Duration × combined bitrate ÷ eight = estimated file size. This uses decimal MB and GB.
How video file size is calculated
Bitrate is the amount of data used each second. Add the average video and audio bitrates, multiply by the running time and divide by eight. The answer uses decimal MB and GB, as storage and upload limits commonly do.
Why the finished file may be different
This is an estimate, not a promise. Variable bitrate, container overhead and encoder behaviour can move the final number. Use the average bitrate reported by your export settings for the closest estimate.
Does resolution determine video file size?
No. A higher resolution often leads an encoder to use a higher bitrate, but two videos at the same resolution can have very different sizes. Duration and average bitrate are what the calculation needs.
Questions about video file size
- How do I calculate video file size?
- Multiply the duration in seconds by the combined video and audio bitrates, then divide by eight to turn bits into bytes.
- How large is a 10-minute video?
- At an average video bitrate of 8 Mbps and audio bitrate of 192 kbps, a 10-minute video is about 614.4 MB. A different bitrate produces a different size.
- Why is my exported video a different size?
- The result assumes the average bitrates you enter. Variable bitrate, container overhead and encoder behaviour can make the finished file different.
- Does changing resolution change file size?
- Not by itself. Resolution can influence the bitrate an encoder chooses, but duration and the actual average video and audio bitrates determine the size.
- Does this calculator upload my video?
- No. It asks for duration and bitrates, not a video file, and all arithmetic runs in your browser.
Need to change a caption file too? Try the subtitle converter. Rooster’s planned export workflow is described on the features page. Rooster is in active development and not released.