Video File Size Calculator: Size from Bitrate and Length
Enter the length of the video and its video and audio bitrates. The calculator shows the estimated file size in MB and GB, and how much space each minute and each hour uses.
Estimates only. Check important results before you rely on them.
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From related categoriesHow to use this calculator
- Enter the length of the video in hours, minutes and seconds.
- Enter the video bitrate in kbps.
- Enter the audio bitrate in kbps.
- Read the estimated file size.
The formula
Worked example
A 1 hour 30 minute video at 5,000 kbps video and 128 kbps audio has a total of 5,128 kbps. Over 5,400 seconds that is 3.46 GB, or about 38.5 MB per minute and 2.31 GB per hour.
Understanding your result
Many videos use variable bitrate, so the real size can be smaller. Container overhead adds roughly 1 to 3%. Higher resolution and faster motion need a higher bitrate.
When to use it
- Plan storage for recordings and downloads.
- Check if a video fits an upload limit.
- Choose a bitrate for a target size.
Assumptions and limits
Uses decimal units (1 GB = 1,000 MB). The result is an estimate for constant bitrate video.
Frequently asked questions
How do I calculate the size of a video?
Multiply the total bitrate by the length in seconds and divide by 8.
What bitrate is 1080p?
About 4,000 to 8,000 kbps for common streaming and recording.
How big is one hour of 1080p video?
Around 2.3 GB at 5,128 kbps.
Why does my file differ from the estimate?
Variable bitrate, codec and container overhead change the size.
Does it include audio?
Yes. Add the audio bitrate in the audio field.