Video Bitrate Calculator

How to use

1. 1Pick a mode at the top: Target file size, Size from bitrate, or Streaming recommendation.
2. 2In Target file size mode, enter the duration (hours, minutes, seconds), pick a target file size in MB or GB, choose an audio bitrate preset (or custom Kbps), then read the required video bitrate from the result panel.
3. 3In Size from bitrate mode, enter the duration, type a video bitrate with a unit (Mbps or Kbps), pick an audio bitrate, then read the estimated file size in MB, GB, or TB.
4. 4Use the duration chips (30 sec reel, 1 min, 5 min, 1 hour, 2 hour film) to load common video lengths with one click.
5. 5Switch to Streaming recommendation, pick a platform (YouTube Live, YouTube upload, Twitch, Vimeo, Facebook Live), choose a resolution, and read the recommended bitrate range plus the one-hour storage footprint.
6. 6Click Copy summary to paste a clean breakdown of inputs and results into a note, ticket, or production worksheet.

About this tool

Video Bitrate Calculator solves the relationship between video bitrate, audio bitrate, duration, and file size for any video file. The Target file size mode takes the file size you want to fit (for example 100 MB for an email attachment or 25 GB for a Blu-ray master), a duration in hours, minutes, and seconds, and an audio bitrate, then returns the exact video bitrate you should set in your encoder so the finished file lands at that size. The Size from bitrate mode runs the formula in the other direction: punch in the video bitrate (Mbps, Kbps, or bps), the audio bitrate, and the duration, and read the estimated MP4, MOV, or WebM file size you will end up with. The Streaming recommendation mode pulls public encoder guidelines for YouTube Live, YouTube uploads, Twitch, Vimeo, and Facebook Live across 480p, 720p, 1080p, 1440p, and 4K resolutions and shows the recommended H.264 bitrate range, a midpoint default, and the storage footprint after one hour at that bitrate so a streamer can size their upload pipe and disk capacity before they go live. Audio presets cover silent video, 64 Kbps voice, 96 Kbps stereo podcast, 128 Kbps YouTube standard, 192 to 320 Kbps high-quality stereo, and 384 Kbps 5.1 surround for cinema mixes, with a custom Kbps field for anything else. Useful for YouTubers fitting a tutorial into a Discord 25 MB upload, Twitch streamers planning their OBS configuration, editors setting export targets in Premiere Pro or DaVinci Resolve, FFmpeg users picking a target -b:v value, and anyone planning storage for a long-form recording. The formula used is file size in bits = (video bitrate + audio bitrate) times duration in seconds, which is how every standard bitrate calculator works for constant-bitrate (CBR) and average-bitrate (ABR) modes. Container header overhead is small (typically under 1%) and is not included. All math runs locally in the browser, so the file sizes, bitrates, and durations you enter never leave your device.

Free to use. Works in your browser. No signup, no login.