How Video File Size Is Calculated
Video file size is determined primarily by bitrate and total duration, not by the video container format (.mp4, .mov, .mkv). The formula is:
Total Size (Megabytes) = [ (Video Bitrate kbps + Audio Bitrate kbps) × Duration in Seconds ] / 8,000
Frequently Asked Questions
Does resolution change file size directly?
Resolution does not affect file size directly — bitrate does. However, higher resolutions require higher bitrates to maintain sharp visual clarity and prevent compression artifacts.
What bitrate is best for 1080p web video?
For standard 24/30fps 1080p video, a bitrate between 8 Mbps and 12 Mbps delivers optimal balance between crisp quality and manageable download bandwidth.