Video / Encoding
Video Bitrate Calculator
Work out a video's file size from its bitrate and length, the bitrate that fits a size limit, or how long a file lasts, with YouTube's recommended upload bitrates as presets.
Video Bitrate Calculator: File size is bitrate multiplied by duration: one megabit per second for one second is 125,000 bytes. The calculator adds the audio bitrate to the video bitrate, and works in decimal megabytes and gigabytes, with binary gibibytes as well, since operating systems differ in which they show. For example, 8 Mbps video and 384 kbps audio for 10 minutes make 629 MB. Runs 100% locally in your browser with zero server file uploads.
- Category
- Video tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
File size = (video + audio bitrate) × duration ÷ 8. Containers add about 1–2%, and encoders with variable bitrate land near, not exactly on, the target. MB and GB here are decimal (1 MB = 1,000,000 bytes); MiB and GiB are binary.
Presets are YouTube's recommended upload bitrates for standard dynamic range video, from its help page as checked on 2 October 2026.
Choosing a bitrate
Fast motion, grain, and fine detail need more bitrate than talking heads or screen recordings. Newer codecs need less for the same quality: HEVC (H.265) and AV1 often look as good as H.264 at 30–50% less bitrate, depending on the content and encoder settings.
To shrink an existing file, use the video compressor; to read a file's actual bitrate and codec, use video info.
Bits and bytes
Bitrates are given in bits per second, file sizes in bytes, and there are 8 bits in a byte, so 8 Mbps is 1 megabyte per second, 60 MB per minute, and 3.6 GB per hour. For units, the file size converter shows MB and MiB side by side.
How to use it
- Choose whether to find the file size, the bitrate, or the duration.
- Enter the other values, or pick a YouTube preset for the video bitrate.
- Read the result in MB, GB, and GiB, or in Mbps for the bitrate.
Privacy & limitations
Everything is worked out in your browser.
Related tools
Frequently asked questions
How do I fit a video under a size limit?
Choose Bitrate, enter the size limit and the length, and use the video bitrate it gives, leaving a few percent for the container. Two-pass encoding hits a target bitrate most accurately.
What bitrate does YouTube recommend?
For standard dynamic range uploads, 8 Mbps for 1080p and 35–45 Mbps for 4K at 24–30 fps, and about half as much again at 48–60 fps; the presets show the full table.
Why is my file a different size?
Variable-bitrate encoders spend more on complex scenes and less on simple ones, so the average is near, but rarely exactly, the target. The container and any subtitles add a little more.
Free tool · runs in your browser · no account required