Video file size calculator
Estimate how large a video will be from its bitrate and duration. Nothing is uploaded — the math runs in your browser.
Why estimate before uploading
File size is decided long before you pick a host: it is bitrate multiplied by duration, plus whatever your audio track costs. Bit rate is set once at export, and every re-encode of an already-compressed video trades a little more quality away.
It matters most when a platform caps uploads. TubeForge accepts up to 95 MB per video on the free tier, which is roughly 20 minutes of 720p or8 minutes of 1080p at the standard bitrates below — worth knowing before you wait on an upload that will be rejected.
Calculator
Common bitrates
| Resolution | Bitrate | Per minute | Per 10 min |
|---|---|---|---|
| 480p | 1.5 Mbps | 11.9 MB | 0.12 GB |
| 720p | 3 Mbps | 22.9 MB | 0.22 GB |
| 1080p | 6 Mbps | 44.9 MB | 0.44 GB |
| 1440p | 16 Mbps | 118.1 MB | 1.15 GB |
| 4K | 40 Mbps | 293.9 MB | 2.87 GB |
Typical values for web delivery, including a 128 kbps audio track. Treat them as starting points — screen recordings and animation compress far below these numbers, while high-motion footage may need more.
The formula
Video size is bitrate × duration. With bitrate in megabits per second and duration in seconds, dividing by 8 converts bits to bytes:
size (MB) = bitrate (Mbps) × 1000 × duration (s) ÷ 8 ÷ 1024
Audio adds its own track on top: a 128 kbps AAC stream contributes about 0.9 MB per minute, which is negligible against 1080p video and can dominate 480p — if your numbers come out higher than the encoder produces, the container overhead or a variable bitrate is usually why.