Video File Size Calculator
Estimate video file size in MB and GB from duration, video bitrate and audio bitrate.
Estimated file size
Know the size before you export
If you need to email a video, fit within WhatsApp's or a form's size limit, or plan disk space for hours of recordings, calculating the file size in advance makes life easier.
How it's calculated
File size is roughly (video bitrate + audio bitrate) × duration ÷ 8. The tool does the maths for you and shows the result in MB and GB.
Planning examples
- A 1-hour 1080p lecture (5 Mbps + 128 kbps): about 2.3 GB
- A 3-minute social video (8 Mbps): about 180 MB
Calculations happen instantly in your browser.
How to use Video File Size Calculator
- Enter the video duration.
- Type the video and audio bitrates.
- The estimated file size is calculated instantly.
- Lower the bitrate if you need to hit a target size.
Why use this tool?
Set up your export correctly the first time so you never run into storage, upload or sharing limits.
FAQ
Why is the real file slightly larger?
Containers add a small overhead (usually 1–3%) for headers and indexes.
Is the result accurate for variable bitrate (VBR)?
If you enter the average bitrate for VBR, the estimate is quite close.
How much space does an hour of 4K take?
At 35–45 Mbps, an hour of 4K video takes about 16–20 GB.
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