How to use this calculator
Use average bitrate for variable-bitrate encoding and add the combined bitrate of all audio tracks. Enter the full recording duration. Resolution alone cannot determine file size because compression settings vary.
The formula
A worked example
A 10 minute video at 20 Mbps with 192 kbps audio uses 20.192 Mbps total. Estimated size is 1.5144 GB, or 1,514.4 MB.
Assumptions & limitations
Decimal storage units: 1 GB = 1,000 MB. Container overhead, subtitles, metadata, and extra tracks not entered are excluded. Variable bitrate makes the result an estimate.
Common questions
Does 4K always create a larger file?
Not at an identical bitrate and duration. Resolution influences the quality achieved at that bitrate.
Why is the file on disk different?
Actual average bitrate, container overhead, or a program’s use of binary units can change the displayed size.
Units reference
The calculation follows the method above. This reference supports the units and conversions.
NIST: binary prefixes and decimal units ↗Formula and worked example checked against automated test cases. About our methodology.