Video File Size Calculator
Estimate how big a video will be from its bitrate and length, with presets for common resolutions. Handy for recording, uploading and storage planning.
Your result appears here.
By Shah Rukh, software developer · Last updated:
Video file size formula
File size (MB) = (video bitrate + audio bitrate) × seconds ÷ 8
Example: 10 minutes of 1080p at 8 Mbps plus 128 kbps audio ≈ 8.128 × 600 ÷ 8 ≈ 610 MB.
Why bitrate matters
Bitrate is how much data is used per second of video. Higher bitrates keep more detail but make bigger files. Modern codecs like H.265 or AV1 can reach similar quality at lower bitrates than H.264.
Need a smaller file? Use the video compressor.
Frequently asked questions
Why is my real file a different size?
Most encoders use variable bitrate, so the real size depends on how much motion and detail the video has.
How big is 1 hour of 1080p video?
At about 8 Mbps, roughly 3.6 GB.
What does Mbps mean?
Megabits per second. Divide by 8 to get megabytes per second.
Related tools
YouTube Thumbnail Downloader
Grab any video’s thumbnail in HD and four smaller sizes.
YouTube Money Calculator
Estimate channel earnings per day, month and year from views.
YouTube Embed Code Generator
Responsive embed code with start time, autoplay and privacy mode.
YouTube Timestamp Link Generator
Link to an exact moment and check your chapters work.
YouTube Title & Description Counter
Check titles, descriptions and tags against YouTube limits.
Engagement Rate Calculator
Engagement % from views, likes and comments.