How this calculator works
A bitrate is the amount of data encoded each second. Multiply the combined audio and video bitrate by the running time, convert bits to bytes, then add the container overhead you expect.
The formula
((video bitrate + audio bitrate) × duration in seconds ÷ 8) × (1 + overhead)Bitrates are normalized to bits per second, durations to seconds, and storage to bytes before calculation.
Worked examples
- 10 Mbps video + 128 Kbps audio for 1 hour is about 4.56 GB before container overhead.
- 5 Mbps video + 128 Kbps audio for 10 minutes is about 384.6 MB before overhead.
- 20 Mbps video + 256 Kbps audio for 30 minutes is about 4.55 GB before overhead.
Frequently asked questions
Why can my exported file be larger or smaller?
Variable bitrate, encoder settings, metadata, and the container change the result. This is an estimate based on the average bitrate you enter.
Is MB the same as MiB?
No. MB uses 1,000,000 bytes; MiB uses 1,048,576 bytes. This calculator keeps decimal and binary units separate.