Free Online Video Length File Size Calculator
Calculate estimated video file sizes and bandwidth requirements based on duration, video bitrate (Mbps), and audio channels.
🎬 Target Resolution & Bitrate Presets
1. Purpose of Video Storage and Bitrate Planning
Digital video workflows require balancing storage capacity against visual encoding quality. Rendering multi-hour event recordings or 4K master files without estimating storage requirements can lead to full hard drives, unexpected cloud storage bills, or upload timeouts.
By specifying duration, video bitrate (Mbps), and audio encoding channels, videographers and editors can forecast disk usage before rendering projects in Premiere Pro, DaVinci Resolve, Final Cut Pro, or HandBrake.
2. Standard Bitrate Recommendations & File Projections
Typical target bitrates for standard frame rates (24-30 FPS) and high frame rates (50-60 FPS):
| Resolution & Preset | Standard (24–30 FPS) | High FPS (50–60 FPS) | Estimated Size (1 Hour) |
|---|---|---|---|
| 4K Ultra HD (3840×2160) | 35 – 45 Mbps | 53 – 68 Mbps | ~16.0 GB – 24.5 GB |
| 1440p 2K QHD (2560×1440) | 16 Mbps | 24 Mbps | ~7.2 GB – 10.8 GB |
| 1080p Full HD (1920×1080) | 8 Mbps | 12 Mbps | ~3.6 GB – 5.4 GB |
| 720p HD (1280×720) | 5 Mbps | 7.5 Mbps | ~2.2 GB – 3.4 GB |
| 480p SD (854×480) | 2.5 Mbps | 4 Mbps | ~1.1 GB – 1.8 GB |
3. Technical Limitations & Bitrate Variations
- VBR vs. CBR Variance: This calculator models Constant Bitrate (CBR) behavior. If you encode using Variable Bitrate (VBR 2-Pass), the final file size will vary depending on scene complexity and motion. Add a 10% to 15% safety buffer.
- Container & Multiplexing Overhead: MP4, MKV, MOV, and AVI containers inject track headers, timing metadata, and index tables, which add roughly 1% to 2% additional data.
- Multichannel Audio: Calculations assume stereo tracks. Uncompressed multichannel audio (such as 5.1 or 7.1 surround sound) significantly increases total file size.
4. Client-Side Execution & Privacy Policy
All calculations execute locally within your browser sandbox using JavaScript. No durations, project specifications, or parameters are transmitted to or stored on our servers.
Standard analytics and third-party advertising scripts (including Google AdSense) operate on this website and may process technical telemetry according to our standard Privacy Policy.
5. Related Media Tools
6. Frequently Asked Questions (FAQ)
How is video file size calculated mathematically?
File size is calculated by multiplying the duration in seconds by the combined total bitrate (video bitrate + audio bitrate in Megabits per second), then dividing by 8 to convert Megabits into Megabytes.
What bitrate should I use for YouTube 1080p uploads?
For standard 1080p SDR video at 24-30 fps, YouTube recommends 8 Mbps. For high frame rate 1080p (50-60 fps), an encoding bitrate of 12 Mbps is recommended.
Why does my actual rendered video file size differ from the calculated estimate?
Estimates assume Constant Bitrate (CBR). Variable Bitrate (VBR) encoding adjusts bitrate based on visual scene complexity. Container metadata, multiplexing overhead, and subtitle tracks also introduce minor variations.
Are my calculation inputs uploaded to remote servers?
No. All computations execute locally in your web browser session using client-side JavaScript. Calculation inputs and project specifications are not transmitted to or stored on our backend servers.