Video file size and bitrate calculator
Enter a video's length and bitrate to see how big the file will be, or a size limit to see the bitrate that fits under it.
Free, no sign-up, and it runs in your browser: nothing is uploaded.
File size
62.9 MB
Export at 12.94 Mbps or less.
How the calculation works
Bitrate is how much data each second of video uses. File size is the video and audio bitrates added together, times the length, divided by eight to turn bits into bytes. A minute at 8 Mbps with stereo audio at 384 kbps is about 63 MB.
The real file comes out a little different: the container adds a small overhead, and most exports use a variable bitrate that spends more on busy scenes and less on still ones. Leave some room when you're aiming for a hard limit.
What bitrate should I export at?
The presets are YouTube's recommended upload bitrates for standard-frame-rate video: 8 Mbps for 1080p, 5 Mbps for 720p, and 35 to 45 Mbps for 4K (the preset uses 35). High frame rates (48 to 60 fps) need about half as much again. Other platforms re-encode what you upload, so a clean 1080p file at these rates is a safe default.
To make the same edit in several aspect ratios, work out each format's size first. MirrorCut exports MP4 up to 4K.
Questions
- How big is a 1 minute 1080p video?
- At YouTube's recommended 8 Mbps with stereo audio, about 63 MB. A recording straight from a phone is usually bigger, because phones tend to record at a higher bitrate than that.
- Why is my exported file a different size?
- Containers add a little overhead, and variable-bitrate exports use more data on busy scenes and less on still ones, so the result lands near the estimate, not on it.
- Is a megabyte 1,000,000 bytes here?
- Yes, it uses decimal megabytes, as macOS does. Windows counts a megabyte as 1,048,576 bytes, so it shows the same file about 5% smaller.
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