How to estimate video file size from bitrate and duration

1. Bitrate in kbps

   "Bitrate (kbps)" is the constant or average encoder bitrate in kilobits per second. Typical: 720p H.264 ~2500 kbps, 1080p ~5000 kbps, 4K HEVC ~20000 kbps.

2. Duration in seconds

   "Duration (seconds)" is the clip length. Convert from minutes (×60) or HH:MM:SS manually — the tool only accepts seconds.

3. Press Run

   Result returns sizeMB = (kbps × seconds) / 8 / 1024, rounded to 2 decimals. Math: kb/s × s ÷ 8 = kilobytes, then ÷ 1024 to MB.

4. Real files include audio + container

   This estimate is video-track only. A 192 kbps stereo AAC adds about 1.4 MB per minute; MP4 container overhead is small (<1%). For exact targets, encode and check, then iterate bitrate.