File size is simply bitrate multiplied by duration. Enter your bitrate and clip length below, add audio if you want, and get the size in gigabytes and megabytes.
How to calculate file size
Multiply the total bitrate in bits per second by the duration in seconds, then divide by 8 to convert bits to bytes. Add the audio bitrate to the video bitrate first if you want the full container size. Drives and streaming specs use decimal GB (a billion bytes), while operating systems often report binary GiB.
One hour of video by bitrate
| Bitrate | Size for 1 hour |
|---|---|
| 5 Mbps | ~2.25 GB |
| 10 Mbps | ~4.5 GB |
| 25 Mbps | ~11.25 GB |
| 50 Mbps | ~22.5 GB |
Frequently asked questions
How do I calculate video file size?
Multiply total bitrate (bits per second) by duration (seconds), then divide by 8 for bytes. 10 Mbps for 1 hour is 4.5 GB.
How big is one hour of 1080p?
At a typical 10 Mbps H.264 bitrate, about 4.5 GB. 4K at 40 Mbps is roughly four times larger.
What is the difference between GB and GiB?
GB is decimal (a billion bytes), used on drives and specs. GiB is binary (1024 cubed), reported by many operating systems. 4.5 GB shows as about 4.19 GiB.
Should I include audio?
Audio adds a little. A 128 to 320 kbps track is small next to video, but over long files it adds up, so include it for accuracy.
How do I find the bitrate to use?
Estimate it with the video bitrate calculator, then bring that number here for your clip length.
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