Video File Size Calculator
Estimate file size from video bitrate, audio bitrate and duration. The result uses decimal MB and GB; resolution alone cannot determine how large a video will be.
This calculator runs from the values you enter and does not require a media upload.
How the video-size calculation works
Size in MB ≈ (video Mbps + audio kbps ÷ 1000) × minutes × 60 ÷ 8. One byte contains eight bits. This calculator uses 1 MB = 1,000,000 bytes and 1 GB = 1,000 MB, and excludes container overhead.
For a ten-minute clip at 8 Mbps video and 192 kbps audio, the estimate is (8 + 0.192) × 600 ÷ 8 = 614.4 MB. The displayed result rounds to 614 MB. Enter zero audio bitrate for a silent file.
| Video + audio bitrate | Duration | Estimated size |
|---|---|---|
| 8 Mbps + 192 kbps | 1 minute | 61.44 MB |
| 8 Mbps + 192 kbps | 10 minutes | 614.4 MB |
| 20 Mbps + 128 kbps | 5 minutes | 754.8 MB |
| 50 Mbps + 192 kbps | 60 minutes | 22.59 GB |
Work backward from an upload limit
For a 25 MB budget and a 60-second clip, the theoretical total bitrate is 25 × 8 ÷ 60 = 3.333 Mbps. With 128 kbps audio, about 3.205 Mbps remains for video before container overhead. Leave headroom rather than targeting the limit exactly.
This is a planning calculation. Compress Video uses quality presets and cannot enforce this bitrate or an exact file size. Verify the exported file.
Why a real file can differ
- Variable bitrate: motion and detail change how much data an encoder uses. Enter the measured average, not just a peak bitrate.
- Extra streams and overhead: subtitles, additional audio tracks and container data also take space.
- Different units: 614.4 decimal MB is about 585.94 MiB. A program using binary units can show a smaller number for the same bytes.
- Resolution is not bitrate: 1080p and 4K describe dimensions. Different codecs and quality settings can produce very different sizes at the same resolution.
Use Metadata Viewer to inspect a file, or read the bitrate-and-duration guide for more context.
Do I need to upload my video?
No. Enter the three numbers; this calculation runs in your browser.
What if metadata gives only a total bitrate?
That total may already include audio and overhead. Do not enter it as video bitrate and then add audio again. Use stream-specific values where available.
Does a smaller estimate guarantee acceptable quality?
No. The formula counts data, not visible quality. Test the actual export at the intended viewing size.
How to Estimate Video File Size From Bitrate and Duration
Estimate a video’s approximate storage size from video bitrate, audio bitrate and running time before exporting.