Video File Size Calculator
Works out how big a video will be before you encode or record it.
File size
—
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
In binary units (powers of 1,024) —
Per minute —
Total bitrate — Mbit/s
The formula
size = (video bitrate + audio bitrate) × length ÷ 8 × (1 + overhead)
Variable-bitrate encodes land near this figure only if the bitrate you enter is the average.
What to watch out for
Sizes come out in decimal units. Switch the unit to GiB to compare with what Windows reports.
Frequently Asked Questions
How big is an hour at 8 Mbit/s?
3.72 GB with 192 kbit/s audio and 1% overhead.