Video File Size Calculator
Estimate video file size from bitrate and duration.
About the Video File Size Calculator
Enter the video bitrate, audio bitrate and duration. The calculator gives the file size in MB and GB, which helps when planning storage, uploads or recording time.
File size is bitrate × duration, plus a little container overhead. Resolution, frame rate and codec decide the bitrate needed for good quality: HEVC and AV1 need roughly half the bitrate of H.264 for similar quality.
The formula
Size (bytes) = (video + audio bitrate) × seconds ÷ 8
Worked example
One hour of 1080p video at 8 Mbps with 192 kbps audio
- (8 + 0.192) Mb/s × 3,600 s ÷ 8 = 3,686 MB
- About 3.69 GB
Questions people ask
Why is my file bigger?
Variable bitrate and container overhead add a few percent.
What bitrate for streaming?
Platforms publish recommended upload bitrates for each resolution.
How much does 4K take?
At 40 Mbps, about 18 GB an hour.