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1080p Video File Size Calculator

Updated · Standard formula, shown below

File size 3.69 GB
Total bitrate
8.192 Mbps
Result
File size
3,686 MB
Result
File size
3.43 GiB
Result

This calculator estimates how big a video file will be. Enter the video bitrate in megabits per second, the audio bitrate in kilobits per second and the length in minutes, and you get the total bitrate and the file size.

Formula

File size (megabytes) = total bitrate (megabits per second) × duration (seconds) ÷ 8, where total bitrate = video Mbps + audio kbps ÷ 1000. GB = MB ÷ 1000; GiB = bytes ÷ 1024³.

  • br: video bitrate in Mbps
  • ab: audio bitrate in kbps
  • mins: duration in minutes (× 60 for seconds)

Worked Example

One hour of 1080p video at 8 Mbps with 192 kbps audio.

  1. Total bitrate = 8 + 192 ÷ 1000 = 8.192 Mbps
  2. 8.192 × 3,600 s ÷ 8 = 3,686 MB
  3. 3,686.4 ÷ 1000 = 3.69 GB
  4. 3,686,400,000 ÷ 1,073,741,824 = 3.43 GiB

Limits and common mistakes

  • Resolution alone does not set the size; the bitrate does. The same 1080p clip can be 4 Mbps or 20 Mbps depending on codec and quality settings.
  • Variable-bitrate encodes use the average bitrate.
  • Container overhead adds roughly 1-2%.
  • To find the bitrate that fits a size limit, reverse it: bitrate (Mbps) = size (MB) × 8 ÷ seconds.
  • A 4 GB limit on some older file systems (FAT32) caps one file at 4,294,967,295 bytes.
Formula used
in br | Video bitrate | Mbps | 8 | 0
in ab | Audio bitrate | kbps | 192 | 0
in mins | Duration | min | 60 | 0
out gb | File size | GB | (br + ab / 1000) * mins * 60 / 8 / 1000 | 2
out tot | Total bitrate | Mbps | br + ab / 1000 | 3
out mb | File size | MB | tot * mins * 60 / 8 | 0
out gib | File size | GiB | mb * 1000000 / 1073741824 | 2

Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.